Prospec 32Gb UDMA 7 CF

Posted on June 6, 2015 by Andrew Astbury

The Prospec 32Gb UDMA 7 Compact Flash Card from Calumet – review

The Prospec 32Gb UDMA 7 Compact Flash Card from Calumet – click image to visit the product order page.

Because I’m something of a photographic ‘old fart’ and have been taking images for a living since before the venerable A1 was a glimmer in some Canon engineers eye, I treat everything new with suspicion!

Back in those days when we shot on film, suspicious gits like me had our favourite films we used. These were whittled down from the vast array on offer, not only on the basis of their performance, but also on reliability.

Did the sprocket holes tear in a particular camera – if they did then to avoid imminent disaster you’d never put that film in that camera.

Were the ‘tails’ always taped to the cassette spool? Christ, that one nearly cost me a boat-load of money at a wedding once – both bride and groom were barristers!

Thank the Lord we don’t have problems like that any more.

But CF cards come with their equivalent problem – card failure.

CF cards are basically Flash RAM, just like SSDs in the latest computers. And as such they are prone to some degree of instant failure over time.

The Way I Use Camera Storage Media

When I’ve finished shooting something I move it from the camera storage to my main imaging machine as soon as possible. Once the shots are on the computer, the card goes back in the camera and is immediately reformatted.

Back when the D3 was Nikon’s flagship I’d had some clonking failures of Lexar CF cards and Sandisk Ultras, when Kevin Treadwell at TFC Birmingham put me on to Delkin cards – and I have never had a problem with them………(see footnote)…

And the two original 16Gb Delkins I bought for the D3 are still going strong to this day!

So when I eventually moved to the D4 I wanted a 32Gb Delkin UDMA 7 to go with the 32Gb Sony XQD, but I couldn’t locate one anywhere.

I was moaning about this to Stuart Tudor-Wood at Calumet Birmingham and he suggested I tried their own Prospec 32Gb UDMA 7 instead.

Can you imagine what the “suspicious old photography fart” in me was saying; I was used to possibly the most reliable memory on the planet, and the priciest; and here was something I’d never heard of, and costing pretty much the same..

I did manage to walk out of the door without paying for it, so that was a small victory – but it only lasted 3 weeks until I was doing another workshop there – he nailed me for it the minute I walked through the door!

So, here we are, two years later. The other day I realised how long I’d had this card in regular use. It’s a mighty rare occurrence for me to have a day shooting long lens action and not generate some use of the CF card.

Even if I’ve only shot to the XQD card, force of habit leads me to format both cards one after the other.

And if I’m going to shoot video I shoot that to the XQD and then remove it if I want to shoot stills, which consequently go to the CF card.

When I’m testing lenses and shooting for workshop slides etc I shoot to the CF card, then stick that in my steam-powered laptop – it can never see my XQD reader and I daren’t even think about asking it to accommodate tethered shooting..

I bought the card a new brother so I had two of them in the 1DX when I went to Norway in February this year.

All in all, looking back through all the image batches I’ve shot I reckoned that this one card had been reformatted 981 times in a selection of camera bodies from a 1DX and 5DMk3 to a D4S, D4, D800, D800E and D810.

In the D4 this card allows me to shoot 41 14bit uncompressed raw files before I hit the end of the camera buffer; which let’s face it, is plenty.

So I promptly set about shooting 20 bursts of 41 frames, wiping the card between bursts, just so that I could say with some degree of certainty that the card had just hit its 1000th reformat.

Now THAT is a good, solid and highly reliable card that has put up with more abuse in the last two years than some of my clients would give their CF cards in a lifetime.

What Do The ‘Hieroglyphics’ All Mean?

I must admit to being somewhat ambivalent to the majority of these speed numbers – at the end of the day, as a photographer you are more interested in sustained write speed than you are in read speed – or at least you should be.

The faster the write speed of the media the longer it takes to hit the end of the camera internal buffer – this means you shoot more sequential frames in a burst.

CF6

This logo means the media is compliant with the CFA’s CF6 specification, which is supposed to provide data transfer rates of 167Mb/sec.

But that quoted transfer rate could be either read or write – they never seem to commit!

CF6 specification means UDMA 7 compliance; whereas UDMA 6 equated to CF 5 specification and transfer speeds of 133Mb/sec.

CF cards have to communicate with a host device – in our case our camera; and UMDA is the most efficient and fastest mode of communication. But not ALL cameras are UDMA compliant. And those that are might not be UDMA 7 compliant.

If a camera is not UDMA compatible then believe it or not, a slower non-UDMA card might make the camera work faster. If you put a UDMA 7 card in a camera that is only UDMA 6 compliant then that’s fine, but communication between the two will be at UDMA 6 speeds.

The moral here is to check your camera specifications, and available firmware upgrades.

What does 1010x mean? Known as the card Commercial X Rating it’s an indication of read speed more than anything else, and basically relates the speed of the card as a multiple of the old CD-ROM standard of 150KBs. So 1010x equates to 151.15Mbs.

But here’s the thing; none of these speeds, theoretical or otherwise, are derived via a camera – they are all acquired on a test-bench computer and a variety of card interfaces.

There is a simple if slightly ‘rough ‘n ready’ test that you can do to check the camera/media combo write speed:

Set the camera to its fastest RAW shooting frame rate (Canon 1DX users note, that’s NOT 14fps!).
Set the burst length to 30 frames.
Put the camera in manual mode, auto iso, and set the shortest shutter speed.

Get a stop-watch and be prepared to start it when the ‘data write’ indicator lights up.

Press and hold the shutter button to start the burst of exposures, take your finger off the shutter button when the camera stops shooting. The indicator light will still be on, and the stop watch should still be running. Stop the clock when the light goes out!

Multiply the number of frames by the size of your RAW file, then divide the result by the time in seconds and you’ll have a rough value for your data write speed in Mb/sec.

In a Canon 1DX the Prospec 32Gb UDMA 7 CF card chugs away at a highly respectable 69Mbs write speed.

32Gb of storage with great reliability and ‘real world’ write speed like that is great – especially for the price.

Nikon Users

If, like me, you mainly shoot uncompressed 14 bit RAW (not an option for Canon shooters) the write speed of the Prospec 32Gb UDMA 7 CF card in a D4/4S will drop to around 41Mbs due to the much increased file size of each RAW frame – 35.9Mb average RAW size, as opposed to the 1DX average file size of around 26.4Mb.

But sensible burst shooting in conjunction with the huge Nikon D4/4S buffer means you will never suffer from ‘buffer lock-out’.

Conclusion

Bearing in mind that this is just my opinion, the Prospec 32Gb UDMA 7 CF card represents exceptionally good value for money. Yes, there are faster cards out there; but I’ve been bitten by both S****** and L**** in the past, and ‘once bitten twice shy’ and all that……

For me the write/format longevity of this card is what strikes me the most, and for the price this card is well worthy of anyone’s consideration.

Prospec 32Gb UDMA 7 CF card,Andy Astbury,Wildlife in Pixels

Two years and over 1000 reformats, the Prospec 32Gb UDMA 7 CF card is still going strong – have a Kite!

Footnote

I’ve just had it confirmed……..the Prospec is actually Delkin; so bearing in mind what I said earlier, the reliability comes as no surprise!

Become a patron from as little as $1 per month, and help me produce more free content.

Patrons gain access to a variety of FREE rewards, discounts and bonuses.

Image Sharpness

Posted on April 16, 2015 by Andrew Astbury

Image Sharpness

I spent the other afternoon in the Big Tower at Gigrin, in the very pleasant company company of Mr. Jeffrey “Jeffer-Cakes” Young. Left arm feeling better yet Jeff?

I think I’m fairly safe in saying that once feeding time commenced at 3pm it didn’t take too long before Jeff got a firm understanding of just how damn hard bird flight photography truly is – if you are shooting for true image sharpness at 1:1 resolution.

I’d warned Jeff before-hand that his Canon 5Dmk3 would make his session somewhat more difficult than a 1Dx, due to it’s slightly less tractable autofocus adjustments. But that with his 300mm f2.8 – even with his 1.4x converter mounted, his equipment was easily up to the job at hand.

I on the other hand was back on the Nikon gear – my 200-400 f4; but using a D4S I’d borrowed from Paul Atkins for some real head-to-head testing against the D4 (there’s a barrow load of Astbury venom headed Nikon’s way shortly I can tell you….watch this space as they say).

Amongst the many topics discussed and pondered upon, I was trying to explain to Jeff the fundamental difference between ‘perceived’ and ‘real’ image sharpness.

Gigrin is a good place to find vast armies of ‘photographers’ who have ZERO CLUE that such an argument or difference even exists.

As a ‘teacher’ I can easily tell when I’m sharing hide space with folk like this because they develop quizzical frowns and slightly self-righteous smirks as they eavesdrop on the conversation between my client and I.

“THEY” don’t understand that my client is wanting to achieve the same goal as the one I’m always chasing after; and that that goal is as different from their goal as a fillet of oak-smoked Scottish salmon is from a tin of John West mush.

I suppose I’d better start explaining myself at this juncture; so below are two 800 pixel long edge jpeg files that you typically see posted on a nature photography forum, website or blog:

image sharpness, Andy Astbury, Wildlife in Pixels, Red Kite

IMAGE 1. Red Kite – Nikon D4S+200-400 f4 – CLICK IMAGE to view properly.

Click the images to view them properly.

IMAGE 2. Red Kite – Nikon D4S+200-400 f4 – CLICK IMAGE to view properly.

“THEY” would be equally as pleased with either…..!

Both images look pretty sharp, well exposed and have pretty darn good composition from an editorial point of view too – so we’re all golden aren’t we!

Or are we?

Both images would look equally as good in terms of image sharpness at 1200 pixels on the long edge, and because I’m a smart-arse I could easily print both images to A4 – and they’d still look as good as each other.

But, one of them would also readily print to A3+ and in its digital form would get accepted at almost any stock agency on the planet, but the other one would most emphatically NOT pass muster for either purpose.

That’s because one of them has real, true image sharpness, while the other has none; all it’s image sharpness is perceptual and artificially induced through image processing.

Guessed which is which yet?

IMAGE 1 at 1:1 native resolution – CLICK IMAGE to view properly.

Image 1. has true sharpness because it is IN FOCUS.

IMAGE 2 at 1:1 native resolution – CLICK IMAGE to view properly.

And you don’t need glasses to see that image 2 is simply OUT OF FOCUS.

The next question is; which image is the cropped one – number 2 ?

Wrong…it’s number 1…

Image 1 uncropped is 4928 pixels long edge, and cropped is 3565, in other words a 28% crop, which will yield a 15+ inch print without any trouble whatsoever.

Image 2 is NOT cropped – it has just been SHRUNK to around 16% of its original size in the Lightroom export utility with standard screen output sharpening. So you can make a ‘silk purse from a sows ear’ – and no one would be any the wiser, as long as they never saw anything approaching the full resolution image!

Given that both images were shot at 400mm focal length, it’s obvious that the bird in image 1 (now you know it’s cropped a bit) is FURTHER AWAY than the bird in image 2.

So why is one IN FOCUS and the other not?

The bird in image 1 is ‘crossing’ the frame more than it is ‘closing in’ on the camera.

The bird in image 2 is closer to the camera to begin with, and is getting closer by the millisecond.

These two scenarios impose totally different work-loads on the autofocus system.

The ability of the autofocus system to cope with ANY imposed work-load is totally dependent upon the control parameters you have set in the camera.

The ‘success’ rate of these adjustable autofocus parameter settings is effected by:

Changing spatial relationship between camera and subject during a burst of frames.
Subject-to-camera closing speed
Pre-shot tracking time.
Frame rate.

And a few more things besides…!

The autofocus workloads for images 1 & 2 are poles apart, but the control parameter settings are identical.

The Leucistic Red Kite in the shot below is chugging along at roughly the same speed as its non-leucistic cousin in image 2. It’s also at pretty much the same focus distance:

Image 3. Leucistic Red Kite – same distance, closing speed and focal length as image 2. CLICK IMAGE to view larger version.

So why is image 3 IN FOCUS when, given a similar scenario, image 2 is out of focus?

Because the autofocus control parameters are set differently – that’s why.

FACT: no single combination of autofocus control parameter settings will be your ‘magic bullet’ and give you nothing but sharp images with no ‘duds’ – unless you use a 12mm fish-eye lens that is!

Problems and focus errors INCREASE in frequency in direct proportion to increasing focal length.

They will also increase in frequency THE INSTANT you switch from a prime lens to a zoom lens, especially if the ‘zoom ratio’ exceeds 3:1.

Then we have to consider the accuracy and speed of the cameras autofocus system AND the speed of the lens autofocus motor – and sadly these criteria generally become more favourable with an increased price tag.

So if you’re using a Nikon D800 with an 80-400, or a Canon 70D with a 100-400 then there are going to be more than a few bumps in your road. And if you stick to just one set of autofocus control settings all the time then those bumps are going to turn into mountains – some of which are going to kill you off before you make their summit….metaphorically speaking of course!

And God forbid that you try this image 3 ‘head on close up’ malarkey with a Sigma 50-500 – if you want that level of shot quality then you might just as well stay at home and save yourself the hide fees and petrol money !

Things don’t get any easier if you do spend the ‘big bucks’ either.

Fast glass and a pro body ‘speed machine’ will offer you more control adjustments for sure. But that just means more chances to ‘screw things up’ unless you know EXACTLY how your autofocus system works, exactly what all those different controls actually DO, and you know how to relate those controls to what’s happening in front of you.

Whatever lens and camera body combination any of us use, we have to first of all find, then learn to work within it’s ‘effective envelope of operation’ – and by that I mean the REAL one, which is not necessarily always on a par with what the manufacturer might lead you to believe.

Take my Nikon 200-400 for example. If I used autofocus on a static subject, let alone a moving one, at much past 50 metres using the venerable old D3 body and 400mm focal length, things in the critical image sharpness department became somewhat sketchy to say the least. But put it on a D4 or D4S and I can shoot tack sharp focussing targets at 80 to 100 metres all day long……not that I make a habit of this most meaningless of photographic pastimes.

That discrepancy is due to the old D3 autofocus system lacking the ability to accurately discriminate between precise distances from infinity to much over 50 metres when that particular lens was being used. But swap the lens out for a 400 f2.8 prime and things were far better!

Using the lens on either a D4 or D4S on head-on fast moving/closing subjects such as Mr.Leucistic above, we hit another snag at 400mm – once the subject is less than 20 metres away the autofocus system can’t keep up and the image sharpness effectively drops off the proverbial cliff. But zoom out to 200mm and that ‘cut-off’ distance will reduce to 10 metres or so. Subjects closing at slower speeds can get much closer to the camera before sharp focus begins to fail.

As far as I’m concerned this problem is more to do with the speed of the autofocus motor inside the lens than anything else. Nikon brought out an updated version of this lens a few years back – amongst its ‘star qualities’ was a new nano-coating that stopped the lens from flaring. But does it focus any faster – does it heck! And my version doesn’t suffer from flare either….!

Getting to know your equipment and how it all works is critical if you want your photography to improve in terms of image sharpness.

Shameless Plug Number 1.

I keep mentioning it – my ebook on Canon & Nikon Autofocus with long glass.

Understanding Canon & Nikon Autofocus

for

Bird in Flight Photography

Click Image for details.

Become a patron from as little as $1 per month, and help me produce more free content.

Patrons gain access to a variety of FREE rewards, discounts and bonuses.

Canon 1Dx & 200-400 f4 L IS USM

Posted on March 3, 2015 by Andrew Astbury

A Nikon users thoughts on using the Canon 1Dx and the 200-400 f4L IS USM.

The Canon 200-400 f4 L IS USM on the 1Dx – overall a staggeringly good pairing that I’m really going to miss when I have to give it back!

For years now, my “standard” wildlife photography lens has been the only 200-400f4 that was ever available, the Nikon.

An epic lens; sharp, good resolution in terms of line pairs per millimetre, and most importantly a boon to in-camera composition. It makes an excellent job of everything I ever ask it to do, from cute Red Squirrels 2 metres in front of me, to thumping great Norwegian Sea Eagles barreling towards me at thirty miles per hour and 30 metres out.

However; it’s not without it’s little idiosyncrasies, in fact I often describe it as “a pig” of a lens to use. Sharpness at 50 meters is questionable, and beyond 75 metres is pathetic – the bottom of a milk bottle could do better.

And it hates teleconverters as a rule – yes it’s sharp, but the resolution drops through the floor.

But if you wanted the compositional versatility that only a 200-400 can give you, then you had no option but to shoot Nikon.

Until that is, the day Canon did the unthinkable and launched their version of a 200-400 f4. And they gave it an internally switch-able 1.4x teleconverter giving you an effective 200 f4 to 560 f5.6 working range – WOW!

I first got hold of one of these babies about 4 weeks after they became available; a client at a Drummond Street workshop I was doing for Calumet brought it in stuck on the front of a 1Dx. I’d torn the lens from his poor hands before he knew what was happening, and whipped it outside, stuck the 1Dx in AF case 2, auto iso, 10 frames per second, manual exposure at 1/2000th and f6.3 and began rattling off frames of passing traffic – I was astounded by the lenses performance.

Over the following 18 months I had one or two further opportunities to “have a bash” with the 1Dx + 200- 400 combo, and it honestly impressed the “bejesus” out of me every time; so much so that I’ve recommended any Canon user that asked me to just BUY ONE. And buy one they did!

I’d also had access to a raft of CR2 raw files shot with this combo from one or two other photographers “who know what they are doing”; especially from my old pal Steve “Judith Chalmers” Kaluski of Untamed Images.

As many folk know, I run Eagle Photography workshop tours to Norway every now and again, and with a winter workshop in February 2015 coming up I was thinking that 200mm to 560mm would make this lens perfect for Norway.

Seeing as I “sold” half a dozen of these lenses for Canon I reckoned they owed me a favour – big time.

So I had a word in a few ears at Calumet, and Reece Piper kindly sent me a 1Dx on loan. Canon UK were not quite so forthcoming – basically saying they hadn’t the stock availability to lend me one for upwards of a month. But my favourite Geordie Lass June Lown came to the rescue and volunteered her newly acquired 200-400, bought on the recommendation of yours truly, for the testing and trip to Norway.

So the scene was set for an epic journey into the inner workings of the lens and the 1Dx you have to hang off the back of it in order to get the “best?” out of it.

Testing & Evaluation

Back in the days of yore, when we all shot film, lenses were tested on a full optical test bench, and the MTF charts produced thusly actually meant something. If the lens tested good, but you got soft images you KNEW you had a camera body lens mount problem, or that the pressure plate that held the film in the proper plane was distorted.

But now, certain manufacturers don’t even measure MTF – they use a calculator to work them out based upon theoretical values NOT real ones. And then we have entities like DXO Labs, who test lenses on cameras. This is lunacy if you are wanting to know about TRUE LENS performance, simply because the quality of lens output (the image projected into the sensor plane) is effected by the vagaries of the item that lives there – the sensor!

And on top of that, when testing under non-laboratory conditions, the performance of the lens is further clouded by inaccurate or unsuitable camera settings, especially those pertaining to auto focus.

So field testing of lenses is not simply a case of “point – squirt – evaluate”; it has to be done with more than a modicum of intelligence when it comes to camera AF settings. You have to do TWO things:

1. UNDERSTAND COMPLETELY how the AF system works and what the parameter control adjustments actually do.

2. Evaluate your subjects behaviour in terms of the aforementioned parameters and adjust them accordingly.

You may be interested in acquiring, for a small fee, my pdf guide to Long Lens Autofocus for Canon & Nikon systems.

Previous experience with the 1Dx had led me to treat the camera with a little trepidation for one single reason – its sensor. As a Nikon user I am used to working with sensors which have perhaps the highest Dynamic Range, lowest Base Noise, and highest Signal-to-Noise (S/N) ratios of any popular 35mm format camera body.

On the left is a Canon 1 Dx CR2 file, right is a Nikon D4 NEF file. Both images were shot at identical ISO, aperture, Ev comp and shutter speed within milliseconds of each other on a dual camera rig. The birds cheek patches are “blown” on the CR2, but the highlight detail is all there in the Nikon file.

This is indicative of the shorter Dynamic Range of the 1Dx sensor. The common perception is that the Nikon D4/4s sensors have roughly 1.5 stops greater dynamic range than the Canon 1Dx – this in effect means that the Nikon speed machine can cope with a least DOUBLE the subject brightness range that the 1Dx can handle.

Note: I find enabling Highlight Tone Priority, shooting menu tab 2 setting D+, does NOT sort the problem out in high contrast situations like this – it just gives you problems with the darker tones in the image.

So are there any other “sensor vagaries” on the Canon 1Dx that can effect the overall image quality – you betcha there is…

When I picked the camera up from Calumet I also “accrued” the 100mm f2.8 L macro lens, specifically to test the sensor base noise levels on a studio hi-speed flash shot I wanted to do. I had already done the setup shots the day before on the Nikon D4, as part of my drive to show single-body owners how versatile they can be with their photography.

You can read my article on the 1Dx sensor noise HERE

Canon 1Dx + 100mm f2.8 macro. Nikon SB800 flash & Calumet ProSeries wireless.

The original CR2 file looks like this (left) and the Nikon setup shot is on the right:

But if we open the images in Photoshop and use a standing wave curves layer over the top of them – as we would do when retouching the images – we see the extreme pattern noise in the 1Dx sensor (above), while we have virtually none in the Nikon file.

We can see more clearly the pattern noise in the 1Dx sensor if we view the images at 100% magnification.

Custom Curve layer at 100% – now that pattern noise on the Canon sensor is obvious.

We can derive from this shoot/test that the Canon 1Dx is a bit more “photon-hungry” than your average Nikon pro body sensor, but then doesn’t have the dynamic range capability to cope with lots of photons when it sees them.

Now let’s be real about all this for a moment; the 1Dx sensor is old tech in all fairness to Canon, though I’ll counter that by throwing the venerable Nikon D3 into the argument – that body is older than a 1Dx and has a sensor that performs far better in both dynamic range and base noise departments.

In reality though, the pattern noise, though always present in 1Dx images, is usually hidden or masked by actual image/subject detail so that, for the most part, you don’t see it AT ALL – just don’t try going for low ISO when photographing the “Black Cat in the Coal House at Midnight”, with a 1Dx if you have an aversion to heavy Photoshop work.

As I said before, as a Nikon user, the sensor output of the 1Dx leaves me grimacing a little to say the least. But, climbing back on the fence of neutrality I can see that dedicated Canon users might not notice the problems I see if only on the basis of “what you’ve never had you never miss”.

And as I was to discover, there’s something of a bonus with this sensor that this Nikon user was not expecting…..more later.

The ongoing banter between Nikon and Canon users is all very well, and usually good for a bit of a laugh between fellow photographers BUT, the reality is this – ALL pro level 35mm format camera bodies from either Canon or Nikon have their good points and bad points; and not a single one stands head- and-shoulders above the rest ON ALL COUNTS.

“What the Lord giveth with one hand, he taketh away with the other” is definitely the one saying that springs to my mind when I get asked about cameras! If you know what you are doing it doesn’t matter which one you use, you’ll invariably find 10 things wrong with it in the first 30 minutes!

I don’t like the feel of the 1Dx – it feels like I’m holding a brick – BUT SO WHAT?
I hate the menu system – it’s mental – BUT YOU GET USED TO IT
I dislike the sensor output – BUT IT’S FIXABLE for the most part.
Buttons & button+button or dial combos – COME ON GUYS, I’m neither double jointed or gifted with four hands!

There used to be a very large version of this image on the web that sums up Canon buttons, but I can only find a small version of it now:

Sadly the “Call Spock” button will not work any more – RIP L.N.

My list of gripes and niggles about the 1Dx could go on but, sensor output notwithstanding, that list could be easily matched or exceeded by my list of niggles about Nikon cameras! So expanding on them any further is a pointless exercise.

Likewise, comparing the two 200-400s as separate lenses is a somewhat pointless activity too – they are different beasts by a country mile, and I would liken the task to attempting a comparison between the iconic Z28 Pontiac Firebird and the equally iconic Aston Martin DBS – as I said, pointless.

But I feel justified in comparing certain aspects of the camera bodies, and seeing as I have already dealt with the sensor comparison to a degree, I’ll now look at the other main fundamental difference I see between Canon and Nikon; and that is the autofocus system.

Autofocus:

I am going to make a very broad and sweeping statement now, and that is Canon autofocus is generally better than Nikon autofocus – FACT.

What do I mean by better?

I mean that it is more controllable and furnishes the user with a greater ability to tailor the autofocus to suit the behaviour of the intended subject. But the more eagle-eyed reader will have spotted my use of the word “generally”; that is there to indicate a caveat – and the caveat is this:

Only if you know what you are doing!

If you DON’T, and you start fiddling with settings such Acceleration/Declaration tracking, then you risk getting in a proper old mess and you’ll wish you HAD bought Nikon!

My soon-to-come Autofocus Guide to Nikon and Canon – available from this very boutique – goes into the nitty-gritty of autofocus in great detail – so buy it..

In a nutshell, you can tailor the Canon autofocus system to cope with how the subject moves ALONG the lens axis; that’s where your AF has to do the most work. Is it moving towards the camera at a constant speed, or is it moving towards the camera in a stop-go-slow-fast-slow manner? With the Canon 1Dx AF system you have 5 different settings you can use to cover this manner of movement. And these settings are all independent of your AF point group settings.

On a Nikon you have NO independent way of setting the camera to cope with this aspect of subject movement. Using a nine point group on a Nikon tends to favour subjects that move in a constant direction and speed, while the 21 point group favours the more erratically moving subject; which has always seemed a little silly to me and somewhat short-sighted of Nikon.

After 6 weeks of working with the 1Dx in conjunction with the 200-400mm on all manner of moving subjects in terms of size, speed and proximity to the camera I have come to the conclusion that only Cases 2 & 6 are of any real use to me as a wildlife photographer. But I have a tendency to select Case 3 and modify it in terms of Tracking Sensitivity and Acceleration/Declaration Tracking as a scene/subject presents itself.

The third parameter adjustment – AF Point Switching – for the most part I have tended to leave at the default setting of 0, though a setting of 1 has proved useful when dealing with the more erratically moving subject when you too are moving somewhat erratically, such as being in a small boat at sea.

White-tailed Eagles locking talons – 1Dx + 200-400 hand held from boat, AF Case 6, 9 point AF expansion, AF point switching +1, Manual Exposure, Auto ISO 1/2000th, f6.3 ISO 640

For the sort of work that I do within this focal length range, I would only ever use the AF Area Modes of Spot, Expanded (what I call 1 with 4 friends) and Expanded AF Surround ( 1 with 8 friends). Under NO circumstances do I want to leave the camera to decide on what part of the subject I’m focussing on, so Zone and Auto are off my radar. For the same reason I never use the 3D tracking mode on my Nikons. But having said that, I can very well envisage photographers using much shorter focal lengths benefiting from the other modes in certain circumstances due to the greater inherent depth of field they have at their disposal.

But what impresses me most is the speed of the AF using this camera and lens combination, it makes my D4 and Nikon 200-400 look like a clockwork toy; even though I always thought it was fast enough….

1Dx + 200-400 hand held from boat, AF Case 6, 9 point AF expansion, AF point switching 0, Manual Exposure, Auto ISO 1/2000th, f6.3 ISO 640

I only hit the AF activation on this bird a split second before the shot was taken – razor sharp, see for yourself:

So, I get to this juncture and have to start asking myself a couple of questions:
1. Would this shot, for instance, look even better via a Nikon D4/D4S sensor ?
2. Would I have got this particular shot using the D4 or a D4S and my Nikon 200-400?

The answer to the first question is YES – it would; there would be somewhat less noise for starters, and the extra dynamic range would at least facilitate easier processing. Being so used to NEF files I find I have to do a more delicate balancing act between highlight and shadow tones when processing 1Dx CR2 files.

Using the 1Dx I’m a lot more concious of the fact that I need to “watch” my highlights when shooting, and that when it comes to processing it’s like I’ve gone back to 12bit RAW files – and it’s years since I’ve processed one of those babies!

The answer to question 2 though is a little more problematic. Under the EXACT same circumstances the answer is most likely a NO as it was basically “snap-shot”, and that sort of shooting rarely works out too well on Nikon using an f4 lens when a fast-moving subject is right on top of you.

Using an f2.8 would have pulled this shot off under the same circumstances without a problem.

Had I framed up on this eagle 4 or 5 seconds beforehand and let the AF track it until it got to this position then YES I would have got the same result; as long as I had been in a 21 point group. But I usually don’t favour a 21 point group on Nikon because it’s just that bit harder to be precise – I want focus on the eagles eye and I couldn’t give a you-know-what about its other bits – so I usually opt for a 9 point group.

Bearing in mind that this bird is DECELERATING RAPIDLY, the Nikon 9 point group and its fixed “speed tracking preset” might allow the predictive side of the Nikon AF system to advance the focus a little closer to the camera than needed at the moment the shutter opens; because the “preset” is more geared toward a CONSTANT subject speed.

And seeing that the camera isn’t exactly stable either, being in a small boat, the new Nikon 4 point group might have made an even bigger cock-up because it always attempts to focus on the nearest point – which ISN’T the eagles eye.

It’s all about the Accel/Decel tracking…..(ADT – my acronym!)

On the 1Dx Canon give you 5 totally independent ADT settings, and Nikon give you 2 fixed presets which are enslaved to separate AF point groups.

Shooting large subjects at distance – such as football – makes for light work in terms of ADT and predictive AF due to the inherently large depth of field for any given f-number. But shoot smaller, faster moving subjects at much shorter distances and those same ADT settings will make a huge difference to the focus accuracy of the captured image.

When shooting somewhat slower moving subjects I always like to switch to a single AF point and place it over the subjects eye.

I like the Spot AF setting on the 1Dx for this sort of work, especially when I can get the composition I want using one of the centre diagonal cross-type sensors, as in this Lynx below:

1Dx + 200-400 at 400mm AF Case 2, spot AF, Manual Exposure, Auto ISO 1/250th, f7.1 ISO 1000 IS Pos 2 – just because I could!

1Dx + 200-400 at 400mm AF Case 2, spot AF, Manual Exposure, Auto ISO 1/250th, f7.1 ISO 200 IS Pos 2 – just to see HOW low I could go!

The Arctic Fox above is shot with Spot AF using a conventional cross-type sensor from the centre left column.

The Wolves below are shot with a diagonal cross-type sensor from the centre column placed over the right eye of the wolf in the middle of the shot, but this time I’m in AF point expansion – 1 with 4 friends – with AF point switching set to +1. This covers off any movement of the wolfs eye up, down, left or right and increasing the point switching from 0 to +1 means that the active Af point will switch to one of those “4 friends” in order to follow the eye if I can’t move the camera fast enough:

1Dx + 200-400 at 366mm AF Case 2, single point AF expansion, Manual Exposure, Auto ISO 1/1000th, f7.1 ISO 4000 – I’m being a bit more sensible now – if you call standing taking pictures of this pair of bad boys with nothing twixt me and them except fresh air sensible!

Canon Spot AF uses just the centre portion of the selected AF sensor and so you can do some very precise focussing using this AF mode.

Where I find it a real boon is when working off a tripod or from a hide where the camera is rock steady on some form of gimbal or ball head, as in this type of shot. And it really comes into its own when using the 1.4x built-in TC on the 200-400:

As you can see from the screen-grab below I have a single AF point selected and located exactly where I want it:

What you can’t see is that Spot AF – which I think Canon ought to re-name “precision” – is only using the centre portion (perhaps 50%) of the area marked in red; so the main focus is concentrated where the eagles beak has dug into the side of the Pine Martens head – very cute and cuddly I must say…

Autofocus Conclusion:

Nikon AF is rather “simplified” and to be honest it has served exceptionally well over the years. But the one niggle I’ve always had is that I WANT to dictate what the AF does, and how and when it does it – I loathe and detest being dictated to, especially by some algorithm written by lab tech who wouldn’t know his “arse from his elbow” when it comes to a good picture.

It’s as if those Nikon guys think I’m an idiot and they know best – it’s not true fellas!

In all fairness, they sell cameras to folk who “aspire”, and those folk need some sort of instant gratification. Also, those same folk would not do the sort of photography that I do “as norm” – yes, I AM NIKON; but I am also a minority!

So I can see why Nikon make use of “preset averages” in a lot of their control algorithms – I just wish they made pro versions of their cameras with a lot of these so-thought-of Intelligent functions left out; I for one would certainly be a lot more chilled out of they did.

Canon have always been notorious for crediting their users with more than a modicum of intelligence, yet they still give the “L plate” folk half a chance by offering certain levels of automation and presets.

As someone who uses all the facilities on a camera body close to the boundaries of their design criteria – and sometimes past ’em! – I find the 1Dx AF system fabulous in terms of both speed and tractability, and it negates all the niggles and gripes about the Nikon system that I have soon got to return to….

Unless of course some retailer, or those lovely guys at Canon take pity on me!

A Nikon Users Final Judgement on the 1Dx + 200-400mm f4 L IS USM

For the least 6 weeks I’ve been on something of a journey that’s for sure.

Strange “buttonograhy” has caused me some head-scratching! I’m a back button focus man myself, so no prizes for guessing which button has given me most confusion – that’s right, the STAR BUTTON!

My brain simply cannot retain what its function is, so when I hit it accidentally with a gloved thumb, I’ve developed a really simple remedy for getting rid of it – TURN THE CAMERA OFF then back on again! That’s a proper Andy Pandy fix that is!

When I get into situations where my subjects are moving into and out of the sun, and scene contrast changes constantly, I still adopt my preferred method of shooting, and that is FULL MANUAL with auto ISO.

The venerable Nikon D3 didn’t handle this too well; the ISO was always a “little sticky” at at coming back down to the lower numbers. The D4 is a lot better, but still comes a little unstuck from time to time.

The Canon 1Dx has performed flawlessly and has just come back from 7 days in Norway where it has been permanently in Manual Exposure with Auto ISO from the very first to the very last frame of the trip, and the Auto ISO function has performed perfectly on every frame.

Here is a situation where this method of shooting paid dividends, with one of the most rarely seen raptors on the planet – the Goshawk:

Goshawk in the rain – 1/60th sec, f5.6, Manual Exposure + Auto ISO 12800

We were in the darkest heart of a chunk of Boreal Forest, at dawn, and it was chucking it down with rain – gloomy is not a word that does the lack of light justice.

Like a ghost this male Goshawk materialises in front of us and we need to get the shots. With so little light, and the teleconverter switched in we need to pick the shots off each and every time the bird stops moving its head. So the fastest speed we can use is 1/60th sec, which on a gimbal mounted rig at 560mm is just do-able with good technique.

Slipping the IS into Mode 2 and using Spot AF continually on the Goshawks eye we got a large number of razor sharp images in the poorest light I think I have ever shot in.

Here is a 100% crop from that image:

Now considering that this image is from a sensor that I’m not overly keen on, let’s compare it to a shot on a sensor I’m usually far happier using – that of a D4S, that happened to be about 3 feet to my left and operated by a client, Mr. Paul Atkins, using the Nikon 200-400:

The same 12800 ISO, both these shots are pretty much straight from the sensor with minimal processing.

Well, I know which I prefer, and it isn’t the one done with a black lens!
A lot of folk think 400 ISO is high – well it isn’t; even though it used to be.

As I have said before in this article, the 1Dx sensor – as far as this Nikon user is concerned – is a little short in the performance stakes; but is it?

At more conventional speeds below 3200 ISO I firmly come down on the side of Nikon.

From 3200 ISO to 5000 ISO I don’t think there is much between them, but above 5000 ISO the Canon 1Dx excels by a country mile; and Nikonophilles can argue the toss with me ’til the cows come home – but I have the images to prove it – so “boo-hoo, sucks to you chaps”…

With all DSLRs, as we increase ISO we shorten Dynamic Range, but it would appear that, even though the 1Dx is shorter than a D4S in that department to begin with, it hangs on to it a lot longer – and that means more images you can make money from; or win competitions with, which ever floats your boat.

When the end of the Universe comes and it’s “lights out” for everyone, just make sure you’ve got a 1Dx in your hand – Shutterstock and Getty will rip your arm off for the shots ‘cos they’ll still be around somewhere, and God won’t get rid of them that easy!

Sadly, I’ve got to give the 1Dx back to Calumet so that they can hire it to some un-appreciative plebs and recoup the dough they’ve lost while yours truly has been jollying it up with the Vikings.

And as for the glorious 200-400, well, that’s got to go back to the lovely June Lown who loaned it to me in the first place.

So many thanks to June, and to Reece Piper from Calumet for agreeing to the long loan 1Dx, and to John Willis from Calumet Manchester for knowing everyone, and for “lubricating the gears” that make the world go around.

In closing I suppose I need to answer the question I’ve been asked a lot since word of my Canon-ising escaped into the general UK wildlife scene – am I ditching Nikon?

No is the short answer; not even if I could afford to.
BUT, if I could afford to I WOULD buy a 1Dx and 200-400 f4 L IS USM – today!

I would dump my Nikon 200-400, but keep the D4/D4S for use with a big prime. But given the choice my standard wildlife “go to” lens would be the Canon 200-400 in conjunction with a 1Dx. It would get more shots than it would lose me, and Canon can always get rid of my gripes about the sensor by upgrading it – as long as they don’t lose the superb high ISO performance.

Right, that’s it – I’m off to go curl up in a corner of my office and cry at the thought of giving this gear back to its rightful owners….

I WANT THIS RIG…do I really have to give it back?

Please consider supporting this blog.

View Autofocus Points in Lightroom

Posted on February 1, 2015 by Andrew Astbury

Mr. Malcolm Clayton sent me a link last week to a free plug-in for Lightroom that displays the autofocus points used for the shot, plus other very useful information such as focus distance, f-number and shutter speed, depth of field (DoF) values and other bits and bobs.

The plug-in is called “Show Focus Points” and you can download it HERE

Follow the installation instruction to the letter!

Once installed you can only launch it from the LIBRARY MODULE:

Accessing the Plug-in via the Library>Plug-in Extras menu CLICK to view LARGER

You will see this sort of thing:

The “Show Focus Points” for Lightroom plug-in window. CLICK to view LARGER.

It’s a usefull tool to have because short of running the rather clunky Canon DPP or Nikon ViewNX software it’s the easiest way of getting hold of autofocus information without sending the image to Photoshop and looking through the mind-numbing RAW schema data – something I do out of habbit!

It displays a ton of useful data about your camera focus settings and exposure, and the autofocus point used – be it set by you, or chosen by the camera.

As far as I can see, the plug-in only displays the main active autofocus point on Nikon D4 and D4S files, but all the autofocus group as well as active points seem to display when viewing .CR2 Canon files as we can see on this very impressive car number plate!:

Screen grab of an unprocessed 1Dx/200-400/TC shot I did while testing the tracking capabilities of the Canon lens with the TC active – the REAL image looks more impressive than this! I’m actually zooming out while tracking too – this is around 200mm + the 1.4x TC. CLICK to view LARGER

Canon 1Dx in AF Point Expansion 4 point; what I call "1 with 4 friends".

Canon 1Dx in AI Servo AF Point Expansion 4 point; what I call “1 with 4 friends”. CLICK to view LARGER.

Canon 1Dx in AI-F autofocus showing all autofocus points used be the camera.

Viewing your autofocus points is a very valid learning tool when trying to become familiar with your cameras autofocus, and it’s also handy if you want to see why and where you’ve “screwed the pooch” – hey, we ALL DO IT from time to time!

Useful tool to have IMO and it’s FREE – Andy likes free…

Cheers to Malc Clayton for bringing this to my attention.

Become a patron from as little as $1 per month, and help me produce more free content.

Patrons gain access to a variety of FREE rewards, discounts and bonuses.

Speed Light Photography

Posted on September 23, 2014 by Andrew Astbury

Speed Light Photography – part 1

First things first, apologies for the gap in blog entries – I’ve been a bit “in absentia” of late for one reason or another. I’ve got a few gear reviews to do between now and the end of the year, video tutorial ideas and requests are crawling out of the woodwork, and my ability to organise myself has become something of a crumbling edifice!

I blame the wife myself………………..

But I’ve come to the conclusion that for one reason or another I’ve become somewhat pigeon-holed as a wildlife/natural history photographer – going under the moniker of Wildlife in Pixels it’s hardly a big surprise is it..

But I cut my photographic teeth on studio product/pack shot and still life work – I loved it then and I still do. And there’s NOTHING that teaches you more about light than studio work – it pays dividends in all aspects of photography, wildlife and landscape work are no exception. Understanding how light behaves, when it’ll look good and when it’ll look like a bag of spanners is what helps capture mood and atmosphere in a shot.

The interaction between light and subject is what makes a great image, and I do wish photographers would understand this – sadly most don’t.

To this end I’ve begun to teach workshops that try to give those attending a flavor of the basic concepts of light by introducing them to the idea of using their speed lights to produce images they can do 365 days a year cum rain or shine – high speed flash, and simple product still life.

Both styles demand a high level of attention to detail in the way the light produced by the speed lights bends and wraps around the subject. Full-blown studio lights have the benefit of modelling lights so that you can see this before you take the shot, but using speed lights means you have to imagine what the light is doing, so it’s level of difficulty begins high, but decreases with practical experience.

A basic 3 light setup with speed lights can produce some really soft and moody lighting with ease.

A basic 4 light setup with speed lights can produce some really soft and moody lighting with ease.

This Black Label shot went a bit bonkers in the final stages with the addition of smoke, but it gives you an idea of the subtlety of lighting that can be achieved with speed lights.

As for the setup, here’s a shot before I introduced the glass….

Simple setup for the Black Label shot – note the well-appointed studio!

…featuring that most valuable of studio photographers tools, the Voice Activated Light Stand..!

Four SB800’s in all, the one on the right is running at 1/2 power and is fitted with an Interfit Strobies softbox and is double diffused using a Calumet 42″ frame (available here) and white diffuser – this constitutes the main light.

Just look at the size of the diffused disc on the face of that 42″ frame – all that from a poxy 2″x1″ flash head in less than 16″ – epic!

The SB800 on the left, fitted with another softbox is turned down to 1/64th power, and is there solely to illuminate the label where it wraps around the left edge of the bottle, and to get a second neck highlight. Although their is light emanating from it, its greatest effect is that of “bouncing” light from the right hand source back in to the bottle.

The V.A.L.S. is fitted with a third speed light that has a diffused snoot – note the expensive diffusion material and the highly engineered attachment method – kitchen towel and rubber band! The sole purpose of this tiny soft light is to just help pull out the left side of the bottle cap from the intensely dark background towards the top of the shot.

The 4th SB800 is fitted with a 30 degree honeycomb and a “tits ‘n ass”; or TNA2 to be more correct; filter just to give a subtle warm graduation to the background.

Speaking of the background, this is a roll of high grade tracing paper – one of the most versatile materials any studio has, both as a front lit or back lit background, or as a diffusion material – just brilliant stuff, second only to Translum plastic, and a shed-load cheaper.

At the other end of the speed light photography spectrum is the most enjoyable and fascinating pastime of high speed liquid motion photography – a posh way of saying “making a mess”!

It doesn’t have to be too messy – just don’t do it on your best Axminster!

By utilising the IGBT (Isolated Gate Bipolar Transistor) circuitry given to us in speed lights we can deploy the very fast tube burn times, or flash durations, obtained at lower output power settings to our advantage.

Simple shots of water, both dyed and clear can produce some stunning captures:

Streams of water captured back lit against a white background illuminated by two speed lights.

The background for this shot (above) is an A1 sized sheet of white foam board illuminated by a pair of SB910s. The internal reflector angle is set to 35mm and the two speed lights are placed on stands about three feet from the background, just out of shot left and right, and aimed pretty much at the center of the board to facilitate a fairly even spread of light.

The power output settings for both speed lights is set to 1/16th which gives us 1/10,000th of a second flash duration.

Switching to tracing paper as a back lit background immediately puts us at a disadvantage in that it’ll cut the amount of light we see at the camera. But a back lit background always looks just that little bit better as it makes your lighting more easy to shape and control.

Doubling the speed light count behind the trace background to 4 now gives us the power in terms of guide number equal to your average studio light – but with full IGBT advantages.

Working a little closer to the background than we were with the white board/reflected light method we can very easily generate a smooth white field of 255RGB which will make our liquid splash shots really punchy:

Working about 3 feet from a translucent background illuminated by 4 SB800’s gives us a much flatter white background, especially when deploying a 150mm or 180mm macro lens.

Shot with a 180mm macro lens at ISO 260 and f16 we have bags of depth of field on this shot.

Using 4x SB800s we can dial in the correct background exposure using the flash output power and camera ISO – we want a background that’s just on the verge of “blinkies”. If we over expose too much for the background the light will wrap around the liquid edges too much, washing out the contrast and flaring – that’s something that muppet on Adorama TV doesn’t tell you!

Take a few shots holding the glass by the rim gives us a clean foot to the glass, so we can now go and make a nice composite in Photoshop:

Composite of a couple of splash shots and a couple of “clean foot” images….

Happy sodding Valentines day for next year everyone……..yuck, but it’ll sell all day bloomin’ long!

A while ago I posted an entry on this blog about doing splash shots using a method I call “long flash short shutter” HERE.

All the shots on this entry have been taken using the “short flash long shutter” method.

This latter method is the more versatile one of the two because it has a more effective “motion freezing” power; the former method being speed-limited by the 1/8000th shutter speed – and it’s more costly on batteries!

BUT………there’s always one of those isn’t there…?

Short flash long shutter utilises the maximum X-synch speed or the camera. This is the fastest speed we can use where the sensor is FULLY open, and it’s most commonly 1/250th sec.

Sussed the massive potential pitfall yet?

That’s right – AMBIENT LIGHT.

If any ambient light reaches the sensor during our 1/250th sec exposure time then WE WILL GET MOTION BLUR that will visually amount to the same sort of effect as slow synch, sharp image with under exposed blur trails.

So we need to make sure that the ambient light is low enough to render a totally black frame.

The “long flash short shutter” method works well in conditions of high ambient provided that the action can be frozen in 1/8000th sec. If your camera only does 1/4000th sec then the method becomes somewhat less useful.

Freezing action depends on a number of things:

1. Is the subject falling under gravity or rising against it?
2. How far away is the subject?

A body falling under gravity is doing around 10mph after it’s fallen 2 feet from a dead start, and a car doing 100mph looks a lot slower when it’s 200 yards down the road than it does when it’s 20 yards away.

Similarly, if we have a cascade of liquid falling under gravity through the frame of our camera and (to avoid the jug or pouring vessel) the liquid has fallen 6 inches when it enters the top of the frame, and 30 inches when it vacates the bottom of the frame; we have to take a few things into consideration.

The liquid is faster at the bottom of the frame than at the top – think Angel Falls – the water pulls itself apart (that’s why the images can look so amazing).
If we shoot close with a short lens the speed differential across the frame will be the same BUT the overall speed will be a little more apparent than if we shoot with a longer lens from further away.

An SB910 has a 1/16th power output duration of 1/10000th sec and an SB800 1/10,900th at the same output setting (OEM-quoted values). With a 70mm lens close up this can make a subtle difference in image sharpness, but fit a 180mm and move further away from the subject to maintain composition, and the difference is non-existent.

If you are throwing liquid upwards against gravity, then it’s slowing down, and will eventually stop before falling back under the effects of gravity – quite often, 1/8000th is sufficient to freeze this sort of motion.

Both “long shutter short flash” and “short shutter long flash” are valid methods, each with their own pluses and minuses; but the method I always recommend people start with is the former “long shutter” method – it’s easier!

When a shot features a glass remember one thing – drinking glasses were invented by a race of photographer-hating beings! Glasses transmit, reflect and refract light through a full 360 degrees and you can really end up chasing your tail trying to find the source of an errant reflection if you don’t go about lighting it in the correct manner.

And if you put liquid in it then things can get a whole lot worse!

I’ll be doing some very specific workshops with Calumet in the near future that will be all about lighting glass and metal, gloss and matte surfaces, so keep your eye open if this sort of thing interests you – IT SHOULD ‘cos it’ll make you a better photographer….!

The simplest “proper” glass lighting method is what we call “bright field illumination” and guess what – that’s the method used in all the above liquid shots.

Glass Photography – Bright Field & Dark Field illumination.

In the image above, I’ve photographed the same glass using the two ancient and venerable methods of glass photography – one is easy, the other a total pain in the ass; guess which is which!

I’m not going to go into this in detail here, that’ll be in a later post; but BRIGHT FIELD defines the outline of the glass with DARK lines, and DARK FIELD defines the glass white lines of WHITE or highlight.

If you guessed DARK FIELD is the pain the bum then you were right – you will see bits of your “studio” reflected in the glass you didn’t even know existed unless you get this absolutely spot on and 100% correct.

The nice thing about studio-style photography is that you have thinking time, without pressure from working with people, animals or weather and a constantly moving sun. You can start to work up a shot and then leave it over night, when you come back the next day and click the shutter everything is as you left it – unless you’ve had burglars.

You do develop a habit of needing more “grips” gear – you’ve NEVER got the right bit! But then again it’s far cheaper than the bad habit of tripod accumulation like my friend Malc is afflicted with!

Later Folks!

Become a patron from as little as $1 per month, and help me produce more free content.

Patrons gain access to a variety of FREE rewards, discounts and bonuses.

The ND Filter

Posted on July 16, 2014 by Andrew Astbury

Long Exposure & ND Filters

long exposure,slow shutter speed,ND filter,CMOS sensor,noise

A view of the stunning rock formations at Porth Y Post on the Welsh island of Anglesey. The image is a long exposure of very rough sea, giving the impression of smoke and fog. 30 seconds @f13 ISO 100. B&W 10stop ND – unfiltered exposure would have been 1/30th.

The reason for this particular post began last week when I was “cruising” a forum on a PoD site I’m a member of, and I came across a thread started by someone about heavy ND filters and very long exposures.

Then, a couple of days later a Facebook conversation cropped up where someone I know rather well seemed to be losing the plot over things totally by purchasing a 16 stop ND.

The poor bugger got a right mauling from “yours truly” for the simple reason that he doesn’t understand the SCIENCE behind the art of photography. This is what pisses me off about digital photography – it readily provides “instant gratification” to folk who know bugger all about what they are doing with their equipment. They then spend money on “pushing the envelope” only to find their ivory tower comes tumbling down around them because they THOUGHT they knew what they were doing………..stop ranting Andy before you have a coronary!

OK, I’ll stop “ranting”, but seriously folks, it doesn’t matter if you are on a 5DMkIII or a D800E, a D4 or a 1Dx – you have to realise that your camera works within a certain set of fixed parameters; and if you wander outside these boundaries for reasons of either stupidity or ignorance, then you’ll soon be up to your ass in Alligators!

Avid readers of this blog of mine (seemingly there are a few) will know that I’ve gone to great lengths in the past to explain how sensors are limited in different ways by things such as diffraction and that certain lens/sensor combinations are said to be “diffraction limited; well here’s something new to run up your flag pole – sensors can be thought of as being “photon limited” too!

I’ll explain what I mean in a minute…..

SENSOR TYPE

Most folk who own a camera of modern design by Nikon or Canon FAIL at the first hurdle by not understanding their sensor type.

Sensors generally fall into two basic types – CCD and CMOS.

Most of us use cameras fitted with CMOS sensors, because we demand accurate fast phase detection AF AND we demand high levels of ADC/BUFFER speed. In VERY simplistic terms, CCD sensors cannot operate at the levels of speed and efficiency demanded by the general camera-buying public.

So, it’s CMOS to the rescue. But CMOS sensors are generally noisier than CCDs.

When I say “noise” I’m NOT referring to the normal under exposure luminance noise that a some of you might be thinking of. I’m talking about the “background noise” of the sensor itself – see post HERE .

Now I’m going to over simplify things for you here – I need to because there are a lot of variables to take into account.

A Sensor is an ARRAY of PHOTOSITES or PHOTODIODES
A photodiode exists to do one thing – react to being struck by PHOTONS of light by producing electrons.
To produce electrons PROPORTIONAL to the number of photons that strike it.

Now in theory, a photodiode that sees ZERO photons during the exposure should release NO ELECTRONS.

At the end of the exposure the ADC comes along and counts the electrons for each photodiode – an ANALOGUE VALUE – and converts it to a DIGITAL VALUE and stores that digital value as a point of information in the RAW file.

A RAW converter such as Lightroom then reads all these individual points of information and using its own in-built algorithms it normalises and demosaics them into an RGB image that we can see on our monitor.

Sounds simple doesn’t it, and theoretically it is. But in practice there’s a lot of places in the process where things can go sideways rapidly……..!

We make a lot of assumptions about our pride and joy – our newly purchased DSLR – and most of these assumptions are just plain wrong. One that most folk get wrong is presuming ALL the photodiodes on their shiny new sensor BEHAVE IN THE SAME WAY and are 100% identical in response. WRONG – even though, in theory, it should be true.

Some sensors are built to a budget, some to a standard of quality and bugger the budget.

Think of the above statement as a scale running left to right with crap sensors like a 7D or D5000 on the left, and the staggering Phase IQ260 on the right. There isn’t, despite what sales bumph says, any 35mm format sensor that can come even close to residing on the right hand end of the scale, but perhaps a D800E might sit somewhere between 65 and 70%.

The thing I’m trying to get at here is that “quality control” and “budget” are opposites in the manufacturing process, and that linearity and uniformity of photodiode performance costs MONEY – and lots of it.

All our 35mm format sensors suffer from a lack of that expensive quality control in some form or other, but what manufacturers try to do is place the resulting poor performance “outside the envelope of normal expected operation” as a Nikon technician once told me.

In other words, during normal exposures and camera usage (is there such a thing?) the errors don’t show themselves – so you are oblivious to them. But move outside of that “envelope of normal expected operation” and as I said before, the Alligators are soon chomping on your butt cheeks.

REALITY

Long exposures in low light levels – those longer than 30 to 90 seconds – present us with one of those “outside the envelope” situations that can highlight some major discrepancies in individual photodiode performance and sensor uniformity.

Earlier, I said that a photodiode, in a perfect world, would always react proportionally to the number of photons striking it, and that if it had no photon strikes during the exposure then it would have ZERO output in terms of electrons produced.

Think of the “perfect” photodiode/photosite as being a child brought up by nuns, well mannered and perfectly behaved.

Then think of a child brought up in the Gallagher household a la “Shameless” – zero patience, no sense of right or wrong, rebellious and down right misbehaved. We can compare this kid with some of the photodiodes on our sensor.

These odd photodiodes usually show a random distribution across the sensor surface, but you only ever see evidence of their existence when you shoot in the dark, or when executing very long exposures from behind a heavy ND filter.

These “naughty” photodiodes behave badly in numerous ways:

They can release a larger number of electrons than is proportional to their photon count.
They can go to the extreme of releasing electrons when the have a ZERO photon count.
They can mimic the output of their nearest neighbors.
They can be clustered together and produce random spurious specks of colour.

And the list goes on!

It’s a Question of Time

These errant little buggers basically misbehave because the combination of low photon count and overly long exposure time allow them to, if you like, run out of patience and start misbehaving.

It is quite common for a single photodiode or cluster of them to behave in a perfect manner for any shutter speed up to between 30 seconds and 2 minutes. But if we expose that same photodiode or cluster for 3 minutes it can show abnormal behavior in its electron output. Expose it for 5 minutes and its output could be the same, or amplified, or even totally different.

IMPORTANT – do not confuse these with so-called “hot pixels” which show up in all exposures irrespective of shutter duration.

Putting an ND filter in front of your lens is the same as shooting under less light. Its effect is even-handed across all exposure values in the scenes brightness range, and therein lies the problem. Cutting 10 stops worth of photons from the highlights in the scene will still leave plenty to make the sensor work effectively in those areas of the image.

But cutting 10 stops worth of photons from the shadow areas – where there was perhaps 12 stops less to begin with – might well leave an insufficient number of photons in the very darkest areas to make those particular photodiodes function correctly.

Exposure is basically a function of Intensity and Time, back in my college days we used to say that Ex = I x T !

Our ND filter CUTS intensity across the board, so Time has to increase to avoid under exposure in general. But because we are working with far fewer photons as a whole, we have to curb the length of the Time component BECAUSE OF the level of intensity reduction – we become caught in a “Catch 22” situation, trying to avoid the “time triggered” malfunction of those errant diodes.

Below is an 4 minute exposure from behind a Lee Big Stopper on a 1Dx – click on both images to open at full resolution in a new window.

Canon 1Dx
4 minutes @ f13
ISO 200 Lee 10stop

The beastly Nikon D800E fairs a lot better under similar exposure parameters, but there are still a lot of repairs to be done:

A 4 minute exposure on a D800, f11 at 200ISO

Most people use heavy ND filters for the same reason I do – smoothing out water.

The texture of the water in the top shot clutters the image and adds nothing – so get rid of it! D4,ISO 50, 30secs f11 Lee Big Stopper

Then we change the camera orientation and get a commercial shot:

Cemlyn Bay on the northwest coast of Anglesey, North Wales, Approximately 2.5 km to the east is Wylfa nuclear power station. Same exposure as above.

In this next shot all I’m interested in is the jetty, neither water surface texture or horizon land add anything – the land is easy to dump in PShop but the water would be impossible:

I see the bottom image in my head when I look at the scene top left. Again, the 10 stop ND fixes the water, which adds precisely nothing to the image. D4 ISO 50, 60 secs, f14 B&W 10 stop

The mistake folk make is this, 30 seconds is usually enough time to get the effect on the water you want, and 90 to 120 seconds is truly the maximum you should ever really need. Any longer and you’ll get at best no more effect, and at worst the effect will not look as visually appealing – that’s my opinion anyway.

This time requirement dovetails nicely with the “operating inside the design envelope” physics of the average 35mm format sensor.

So, as I said before, we could go out on a bit of a limb and say that our sensors are all “photon limited”; all diodes on the sensor must be struck by x number of photons.

And we can regard them as being exposure length limited; all diodes on the sensor must be struck by x photons in y seconds in order to avoid the pitfalls mentioned.

So next time you have the idea of obtaining something really daft, such as the 16 stop ND filter my friend ordered, try engaging your brain. An unfiltered exposure that meters out at 1/30th sec will be 30 seconds behind a 10 stop ND filter, and a whopping 32 minutes behind a 16 stop ND filter. Now at that sort of exposure time the sensor noise in the image will be astonishing in both presence and variety!

As I posted on my Book of Face page the other day, just for kicks I shot this last Wednesday night:

Penmon Lighthouse in North Wales at twilight.
Sky is 90 secs, foreground is 4 minutes, D4, f16, ISO 50 B&W 10 stop ND filter

The image truly gives the wrong impression of reality – the wind was cold and gusting to 30mph, and the sea looked very lumpy and just plain ugly.

I spent at least 45 minutes just taking the bloody speckled colour read noise out of the 4 minute foreground exposure – I have to wonder if the image was truly worth the effort in processing.

When you take into account everything I’ve mentioned so far plus the following:

Long exposures are prone to ground vibration and the effects of wind on the tripod etc
Hanging around in places like the last shot above is plain dangerous, especially when it’s dark.

you must now see that keeping the exposures as short as possible is the sensible course of action, and that for doing this sort of work a 6 stop ND filter is a more sensible addition to your armoury than a 16 stop ND filter!

Just keep away from exposures above 2 minutes.

And before anyone asks, NO – you don’t shoot star trails in one frame over 4 hours unless you’re a complete numpty! And for anyone who thinks you can cancel noise by shooting a black frame think on this – the black frame has to be shot immediately after the image, and has to be the same exposure duration as the main image. That means a 4 hour single frame star trail plus black frame to go with it will take at least 8 hours – will your camera battery last that long? If it dies before the black frame is finished then you lose BOTH frames……………

Become a patron from as little as $1 per month, and help me produce more free content.

Patrons gain access to a variety of FREE rewards, discounts and bonuses.

Auto Focus Work Out

Posted on July 1, 2014 by Andrew Astbury

Auto Focus Work Out

My recent summer trip to Flatanger in Norway, and to the famous “Eagle Man of Norway” Ole Martin Dahle, proved, as ever, a severe test of the auto focus capabilities of the gear!

We had 4 guys on the trip, 3 Nikon and 1 Canon, and White-tailed Eagles doing more than 40mph and turning on a dime is one of the hardest tests for auto focus tracking and lock on that you can imagine – especially when it’s all done hand held from a boat that’s rolling around in the sea swell.

wildlife photography,auto focus,Nikon,D4,Andy Astbury,eagle,Norway,workshop,camera settings

The Guys – yours truly, Malcolm Clayton and Paul Atkins; and Mohamed El Ashkar (all the way from Cairo!) and our Cambridge “Don” – all trips should have one – Jamie Gundry. Photo by Ole Martin Dahle.

We had a conglomeration of D4’s, D800E’s and 200-400 f4’s, with a smattering of 300mm and 400mm f2.8’s – and then there was Mohamed with his solitary 1Dx and 300 f2.8.

And our target:

Say “Hello” to “Brutus” – an eagle who lives up to his name for sure – a total brute, especially to a boat full of daft photographers! CLICK for larger view.

Just to set the scene with regard to the technical side of things; birds fly into the wind given the choice, and the sun is wherever it decides to be! So the boat driver – Ole – always needs to position the boat so that “wind and sunlight” are coming from pretty much the same direction, otherwise the birds are not front-lit and cast their own shadows across themselves. In other words the images look like crap!

Some birds come towards the boat, take the fish and then turn away; some will do their approach parallel to the boat; and gits like Brutus will fly low and fast straight at you, pick the fish and then turn straight for the boat and climb.

But no matter how they choose to approach the camera boat all the birds pick the fish and go back to where they’ve come from.

Ole has intimate knowledge of these birds as individuals, and so has a damn good idea of what they will do as they come to the boat. This enables him to manoeuvre the boat for the best shots, and this skill is what you pay for.

Perhaps by now you’ve got the general feel for the situation – a boat that’s subject to wave motion and which might suddenly go backwards 10 yards through its own wake – not the steadiest of camera platforms!

Couple that with trying to make the auto focus lock on and track the bird, and maintain a modicum of composition – it’s just damned hard work.

Photographing anything that’s moving is hard work; moving erratically is even harder; and hand holding on an oscillating camera platform makes the job beyond hard. This style of shooting will NEVER yield vast rafts of sharp sequential images – anyone who tells you different is an outright liar. Christ, even licensed FIA F1 ‘togs are on “easy street” by comparison.

Auto focus cannot be set up perfectly for this sort of situation, but understanding it is a MUST if you want to maximise the opportunity.

Auto Focus Choices

There are 3 main things that control the effectiveness of auto focus and AF tracking:

AF Area Mode

AF Tracking Lock-on interval

Frame Rate

(Bare in mind I’m talking Nikon here, but sorting Mohameds’ 1Dx out showed my that Canon AF is pretty much the same).

Now I dealt with the latter in a previous post HERE and so we need to concentrate here on AF area modes in the main.

Let’s look at what we have to work with on a Nikon body – in this case a D4:

Firstly, the AF sensor layout.

All 51 focus sensors, and there approximate layout in relation to the image frame:

All 51 of the Nikon Multi Cam 3500 FX focus sensors – both cross and linear sensors depicted.

Just the Cross-type Sensors:

wildlife photography,auto focus,Nikon,D4,Andy Astbury,eagle,Norway,workshop,camera settings,Nikon Multi-Cam 3500 FX unit

The 15 Cross type focus sensors on the Nikon Multi-Cam 3500 FX unit.

The Linear-type Sensors:

The 36 Linear type focus sensors on the Nikon Multi-Cam 3500 FX unit.

Single Area AF

Single Area, or single point AF.

9 Point Dynamic Area AF:

9 Point Dynamic Area AF

9 Point DA AF as displayed in the viewfinder (drop shadows added in Photoshop behind the dots to aid visibility in this article).

21 Point Dynamic Area AF:

21 Point Dynamic Area AF

21 Point DA AF as displayed in the viewfinder (drop shadows added in Photoshop behind the dots to aid visibility in this article).

51 Point Dynamic Area AF:

51 Point DA AF as displayed in the viewfinder (drop shadows added in Photoshop behind the dots to aid visibility in this article).

As a stills photographer you are using what’s called Phase Detection auto focus (that’ll be another blog post topic!) but it still relies on a mix of contrast,luminosity and colour to work out what it should be concentrating on in the frame.

Consider the following 2 images, A & B:

A. Dark Subject and Light Background.
Subject itself is low contrast, background water is higher contrast. Subject is at 15 meters, Focal Length is 240mm

B. Light Subject against a Dark Background.
Subject now has a slightly higher contrast, and background is lower contrast. Subject 29 meters, Focal length 360mm

Auto focus is dumb; just plain stupid, left to its own devices. It, like me (yep, me dumb too!) favours lighter things with a higher degree of contrast. The lighter something is then the brighter and more saturated it colour is, and this in turn gives it higher localised contrast.

Auto focus will be happier locking on to and tracking Eagle B than Eagle A.

In A, the AF will want to switch to the lighter, more contrasty water behind the bird – unless of course you “hobble it” and stop it from doing so…

And you stop it by BLINDING IT – in other words use LESS active auto focus points!

“If it ain’t got ’em it can’t switch to ’em!”

If all the AF points in use are on the important part of the subject (the EYE in this case) then there’s little or no chance of the auto focus switching to somewhere you don’t want it to go to.

In a perfect world we’d all be using Single Area AF on a tripod and panning away quite happily keeping that single sensor on the targets eye……………oh I wish!!!!!!

51 point AF is out for this sort of work – with what I’ve just written you should now easily understand why.

So we are down to either the 9 point or 21 point Dynamic Areas.

It all comes down to two things:

How steady you can keep the camera.
How big in the frame the birds are – in other words, subject distance.

But accuracy of auto focus will always be improved by using the least number of sensors you can get away with.

Image A. is at 240mm and a subject distance of 15 meters, and Image B. is at 360mm and a subject distance of 29 meters. Both images were shot using 21 point Dynamic Area AF, 1/2000th @ f7 and 1600ISO.

21 point AF, 15 meters and 240mm focal length.

21 point AF, 29 meters and 360mm focal length.

On the upper detail image there’s one, perhaps two of the 21 sensors that are NOT on the subject.

On the second image there are at least 9 sensors out of the 21 in the group that are NOT on the bird.

If the bird in image A. had been 29 meters away I’ll guarantee it would have been out of focus – why?

Lack of good directional light.
Poor subject contrast and illumination.
Brighter, higher contrast background.
More sensors “Off Target”.

And the auto focus hasn’t wanted to wander to the background on image B. because there’s nothing there for it to favour over the main subject.

How Dynamic Area AF Works

9 point DA auto focus uses the single AF point that you select, but activates the 8 points surrounding it. If you, or the subject, or both, move so that the single point you selected comes “off target” then one of those 8 surrounding points will “cover” the error and maintain focus lock and tracking until you get back on target.

In 9 point DA, auto focus ALL the sensors activated are “cross type” sensors, assuming you use a sensor on the vertical center line of the AF grid.

In 21 point DA, auto focus is still centered on the single sensor you select, but now the surrounding 20 are activated. But at least 6 of these sensors will be linear, not cross type sensors.

Auto Focus Senor Types – Cross and Linear (line).

This is going to be immensely paraphrased!

AF sensors need to see edge detail in order to work. A linear sensor can work more effectively when the edge it’s looking at is perpendicular to it.

The more an edge is parallel to said line sensor then the harder time it has in discerning when said edge is sharp or not.

But if we add 2 line sensors together at right angles to each other, then an edge that is parallel to one line is perpendicular to the other – so edge detection is greatly enhanced.

In an ideal scenario 9 point Dynamic Area AF, centered in the middle of the view finder and kept on the eagles head would be the ideal way to go, but with the other circumstances of:

Moving camera platform
Potential closeness of subject (sub 15 meters possible)

then 9 point DA might be a wee bit tight on both counts, and 21 point makes more sense from a tracking and shooting perspective.

But it leads to an initial problem with the auto focus acquiring the target in the first place. You have to pick these eagles up quite a way out, and if one is coming low to the water then there is possibly too much in the frame to act as a distraction to the auto focus unit itself; though this isn’t quite such an issue if the bird is high in the sky.

So my recommendation for any form of bird-in-flight photography is to start out at 9 point DA and see how you get on!

There is always the AF Tracking Lock On feature that you can deploy in order to “hobble” the AF unit from switching to subjects closer to or further away, but if I’m honest I find this the most sticky and difficult aspect of the Nikon system to get a precise handle on. It does exactly “what it says on the tin” but it’s the “when” and “how much by” bits that have me slightly guessing.

Sometimes I put it on long and it basically waits for perhaps 4 or 5 seconds before it tries to switch focus, while at other times it does so in less than half the time. Sometimes I feel it actually diminishes the effectiveness of the “predictive” side of the auto focus tracking unit.

But if I turn it off when hand holding the camera for flight shots then everything turns to crap – so I turn it back on again!

Again, my base recommendations for this are SHORT to NORMAL and see how things go.

One thing that can have a considerable impact on the way you perceive your auto focus effectiveness is how you have your AF release priority set up (CS a1).

There are 4 options:

Release
Focus+Release
Release+Focus
Focus

By default this is set to FOCUS. With the default setting, it’s theoretically impossible to take a soft shot. But in practice that’s not so simple, and I’ve taken many a soft shot when the D4 “thinks” things are sharp; though in the main, that seems to have been cured the minute we got trap focus back with the latest firmware upgrade.

Release means the camera will take shots irrespective of focus being acquired or not. I NEVER use this option.

Focus+Release means that the first frame will only be taken once focus is acquired, and subsequent frames will be taken irrespective of focus. This is one of my preferred options when everything is unstable – that first frame hopefully sets up the auto focus and AF tracking and so everything SHOULD keep the subsequent frames sharp – please note the use of the word “should”!

Both the above release priority modes do NOT slow the frame rate.

Release+Focus – works the opposite way to Focus+Release – it does slow the frame rate down giving the mirror more down-time and so the auto focus system has more time to work. This is my other preferred option, the one I use when the “action” may not be as repeatable.

Focus – This is the option I deploy when shooting from a tripod or when the action is not quite so fast-paced. Again, this option slows the frame rate.

The Back Button Auto Focus Option

I always use the back button for auto focus activation. There are plenty of arguments for doing this, but I just feel it’s darn right more efficient than having AF activation on the shutter button. Just don’t forget to turn AF/Shutter ON to OFF in the menu, otherwise you are just wasting time and effort!

Conclusion

A lot of folk feel that their auto focus is flawed; but more often it is they and their setup choices which are flawed.

There is no blanket panacea or magic bullet setting for your AF system – as with everything else you have to constantly evaluate the light around you, anticipate the shot and make the necessary changes to setup – otherwise it’s going to be a sad day.

But knowing how your gear works and how it reacts under different scenarios is the “meat and two veg” of good photography. Couple that with shot anticipation and the proper corrective measures and it’s off home for tea and medals!

But above all, remember to have a laugh – you’re a long time dead……..

“GIMME SOME, YOU MEAN BARSTARD!”

Become a patron from as little as $1 per month, and help me produce more free content.

Patrons gain access to a variety of FREE rewards, discounts and bonuses.

Trap Focus

Posted on March 18, 2014 by Andrew Astbury

Trap Focus on the Nikon D4

Trap focus comes to my D4 – Yay!!!!!!!!

What was it Nikon said – “we left it off the D4 because no one wanted it”….or words to that effect.

Well, with today’s (March 18th 2014) update version 1.10 trap focus is back – in a fashion.

What is trap focus some may ask. Well it’s basically pre-focusing on a particular distance or spot where you expect the subject to be or to pass through.

As the subject enters the frame and gets closer to the camera it’s also getting closer to the pre-focused distance, and when it reaches the set focus distance the camera actually detects the subject/image is sharp and so takes the shot.

Basically you sit there with the shutter button fully depressed, but no shots get taken until the camera AF system deems the subject is now in focus.

It’s a technique that a lot of sports photographers find very useful, but I find it has very limited use for my wildlife & natural history work. Having said that, it’s got me out of a bind more than once over the years, but ever since the D4 came out you’ve not been able to use it.

The failing lay in the flawed D4 focus priority – even if you told it to only trip the shutter when the image was deemed ‘in focus’ by setting CS a1 & a2 to FOCUS, it would still fire as if a1 and a2 were set to release priority.

But the new firmware update v1.10 has given trap focus back to the D4, but before you start jumping up and down and getting all excited you need to know how to set it up, and bare in mind that “as a technique” trap focus might not suit what you had in mind.

Setup for D4 Trap Focus

Update firmware to v1.10 – read the instructions FULLY before you attempt this, otherwise you may need another camera!
Go to Custom Settings a2 AF-S priority selection and set to FOCUS.
Go to Custom Settings a4 AF activation and set to AF-ON only – this takes to AF activation away from the shutter release button.
Put a wide angle lens on the camera.
Set the lens focus switch to M/A
Set the D4 focus mode selector (the lever on left side of the body front) to AF
Press the AF mode button and rotate the Command Dial (back one) to select AFS and NOT AFC.
Rotate the Sub Command Dial (front one) to select S (single) and NOT Auto.
Focus on your computers monitor screen using either the manual focus ring of the lens or the rear AF-ON button next to the Command Dial.
If you’ve pressed the latter TAKE your thumb OFF!
Move the camera directly away from the computer monitor screen so the image in the viewfinder goes soft.
Jam your finger down on the shutter release. Nothing happens (if it does then start again!).
Keeping that shutter button depressed and NOT touching the lens or AF button, move back towards the computers monitor screen – the shutter will fire when the monitor screen is sharp.

Got that? Good! Oh, and by the way, the award-winning shot you just missed – it would have been epic!

Now you’ve got a D4 that does trap focus.

Now for the trap focus caveats:

Trap Focus only works in AFS – not in AFC.

Trap Focus only works with a single AF sensor, AFS-S – so correct prediction of that one AF sensor/subject alignment to get the required ‘bits” in sharp focus and DoF is going to be difficult.

wildlife photography, common Kestrel, photography technique,manual focus trap,trap focus

Do NOT think you can pull this wildlife shot off using TRAP FOCUS.

By the time the camera has detected the sharp focus and got over the system lock time and triggered the shutter, the bird will be way closer to the camera – and sharp focus in the resulting image will be behind the tail!

This shot is done with a manual focus trap – a completely different technique, as described HERE

The subject is too small and so to close to the camera and 500mm lens for trap focus to work effectively.

However, if you are doing sports photography for instance, you are imaging subjects that are much bigger and a lot further away.

A 500mm f4 on an FX body has over 2 meters depth of field at f5.6 when focused at 40 meters. Take a baseball match for instance – not that I’ve ever covered one mind!

Set the single AF sensor focus distance at home plate.

Then tilt the camera up slightly, or move the sensor with the Dpad so it can’t see/is not overlaying what you just focused on. Hold the shutter button down and wait for a player to make a dive for home plate. As he enters the area of the AF sensor the camera will fire continually if you’re in continuous shooting mode, and will only stop when the camera detects focus has been lost.

Works like a charm!

The key thing is that the depth of field generated by the focus distance makes trap focus work for you – at much shorter distances where depth of field is down to an inch or so if you’re lucky, then couple that with a fast subject approach speed, and trap focus will fall down as a reliable method.

If I’m doing studio flash work like this:

which is never often enough any more! – I sometimes find it useful to use trap focus because it can help doing hand held work under the lowish flash unit modelling lights when you want to make sure eyes are sharp.

Using Trap Focus in a sort of ‘bastardised’ manner can help you maintain sharp focus on models eyes whilst giving you freedom to move around, change composition, zoom etc. by controlling the sharpness of the image with the lens focus ring.

Like I said earlier, it’s a technique that can get you out of trouble every now and again, but up until today you hadn’t got recourse to it on the D4.

But you seriously need to understand the limitations of trap focus deployment before you rush out and use it – you could be very disappointed with the results, and it’ll be all your own fault for trying to bang a square peg through a round hole.

Become a patron from as little as $1 per month, and help me produce more free content.

Patrons gain access to a variety of FREE rewards, discounts and bonuses.

What Shutter Speed?

Posted on March 17, 2014 by Andrew Astbury

Shutter speed, and the choices we make over it, can have a profound effect on the outcome of the final image.

Now everyone has a grasp of shutter speed and how it relates to subject movement – at least I hope they do!

We can either use a fast shutter speed to freeze constant action, or we can use a slow shutter speed to:

Allow us to capture movement of the subject for creative purposes
Allow us to use a lower ISO/smaller aperture when shooting a subject with little or no movement.

Fast Shutter Speed – I need MORE LIGHT Barry!

shutter speed,Red Kite,Andy Astbury,action photography,Wildlife in Pixels

1/8000th sec @ f8, Nikon D4 and 500mm f4

Good strongish sunlight directly behind the camera floods this Red Kite with light when it rolls over into a dive. I’m daft enough to be doing this session with a 500mm f4 that has very little in the way of natural depth-of-field so I opt to shoot at f8. Normally I’d expect to be shooting the D4 at 2000iso for action like this but my top end shutter speed is 1/8000th and this shutter speed at f8 was slightly too hot on the exposure front, so I knocked the ISO down to 1600 just to protect the highlights a little more.

Creative Slow Shutter Speed – getting rid of light.

1/5th sec @ f22

I wanted to capture the movement in a flock of seagulls taking off from the water, so now I have to think the opposite way to the Kite shot above.

Firstly I need to think carefully about the length of shutter speed I choose: too short and I won’t capture enough movement; and too long will bring a vertical movement component into the image from me not being able to hold the camera still – so I opt for 1/5th sec.

Next to consider is aperture. Diffraction on a deliberate motion blur has little impact, but believe it or not focus and depth of field DO – go figure!

So I can run the lens at f16/20/22 without much of a worry, and 100 ISO gets me the 1/5th sec shutter speed I need at f22.

Slow Shutter Rear Curtain Synch Flash

We can use a combination of both techniques in one SINGLE exposure with the employment of flash, rear curtain synch and a relatively slow shutter speed:

6/10th sec @ f3.5 -1Ev rear curtain synch flash

A technique the “Man Cub” uses to great effect in his nightclub photography, here he’s rotated the camera whilst the shutter is open, thus capturing the glowing LEDs and other highlights as circular trails. As the shutter begins to close, the scene is lit by the 1/10,000th sec burst of light from the reduced power, rear curtain synched SB800 flash unit.

But things are not always quite so cut-and-dried – are they ever?

Assuming the lens you use is tack sharp and the subject is perfectly focused there are two factors that have a direct influence upon how sharp the shot will be:

System Vibration – caused by internal vibrations, most notably from the mirror being activated.
Camera Shake – caused by external forces like wind, ground vibration or you not holding the camera properly.

Shutter Speed and System Vibration

There was a time when we operated on the old adage that the slowest shutter speed you needed for general hand held shooting was equal to 1/focal length.

So if you were using a 200mm lens you shot with a minimum shutter speed of 1/200th sec, and, for the most part, that rule served us all rather well with 35mm film; assuming of course that 1/200th sec was sufficient to freeze the action!

Now this is a somewhat optimistic rule and assumes that you are hand holding the camera using a good average technique. But put the camera on a tripod and trigger it with a cable or remote release, and it’s a whole new story.

Why? Because sticking the camera on a tripod and not touching it during the exposure means that we have taken away the “grounding effect” of our mass from the camera and lens; thus leaving the door open to for system vibration to ruin our image.

How Does System Vibration Effect an Image?

Nowadays we live in a digital world with very high resolution sensors instead of film. and the very nature of a sensor – its pixel structure (to use a common parlance) has a direct influence on minimum shutter speed.

So many camera owners today have the misguided notion that using a tripod is the answer to all their prayers in terms of getting sharp images – sadly this ain’t necessarily so.

They also have the other misguided notion that “more megapixels” makes life easier – well, that definitely isn’t true!

The smallest detail that can be recorded by a sensor is a point of light in the projected image that has the same dimensions a one photosite/pixel on that sensor. So, even if a point is SMALLER than the photosite it strikes, its intensity or luminance will effect the whole photosite.

shutter speed,Red Kite,Andy Astbury,action photography,Wildlife in Pixels,vibration reduction,camera shake,mirror slap,sharp images.

A point of light smaller than 1 photosite (left) has an effect on the whole photosite (right).

If the lens is capable of resolving this tiny detail, our sensor – in this case (right) – isn’t, and so the lens out-resolves the sensor.

But let’s now consider this tiny point detail and how it effects a sensor of higher resolution; in other words, a sensor with smaller photosites:

The same detail projected onto a higher resolution sensor (right). Though not shown, the entire photosite will be effected, but its surface area represents a much small percentage of the whole sensor area – the sensor now matches the lens resolution.

Now this might seem like a good thing; after all, we can resolve smaller details. But, there’s a catch when it comes to vibration:

A certain level of vibration causes the small point of light to vibrate. The extremes of this vibration are represented by the the outline circles.

The degree of movement/vibration/oscillation is identical on both sensors; but the resulting effect on the exposure is totally different:

The same level of vibration has more effect on the higher resolution sensor.

If you read the earlier post on sensor resolution and diffraction HERE you’ll soon identify the same concept.

The upshot of it all is that “X” level of internal system vibration has a greater effect on a higher resolution sensor than it does on a lower resolution sensor.

Now what’s all this got to with shutter speed I hear you ask. Well, whereas 1/focal length used to work pretty well back in the day, we need to advance the theory a little.

Let’s look at four shots from a Nikon D3, shot with a 300mm f2.8, mounted on a tripod and activated by a remote (so no finger-jabbing on the shutter button to effect the images).

Also please note that the lens is MANUALLY FOCUSED just once, so is sharply on the same place for all 4 shots.

These images are full resolution crops, I strongly recommend that you click on all four images to open them in new tabs and view them sequentially.

Shutter = 1/1x (1/320th) Focal Length. No VR, No MLU (Mirror Lock Up). Camera on Tripod+remote release.

Shutter = 1/2x (1/640th) Focal length. No VR. No MLU. Camera on Tripod+remote release.

Shutter = 1/2x Focal length + VR. No MLU. Camera on Tripod+remote release.

Shutter = 1/2x Focal length. Camera on Tripod+remote release + MLU – NO VR + Sandbag.

Now the thing is, the first shot at 1/320th looks crap because it’s riddled with system vibration – mainly a result of what’s termed ‘mirror slap’. These vibrations travel up the lens barrel and are then reflected back by the front of the lens. You basically end up with a packet of vibrations running up and down the lens barrel until they eventually die out.

These vibrations in effect make the sensor and the image being projected onto it ‘buzz, shimmy and shake’ – thus we get a fuzzy image; and all the fuzziness is down to internal system vibration.

We would actually have got a sharper shot hand holding the lens – the act of hand holding kills the vibrations!

As you can see in shot 2 we get a big jump in vibration reduction just by cranking the shutter speed up to 2x focal length (actually 1/640th).

The shot would be even sharper at 3x or 4x, because the vibrations are of a set frequency and thus speed of travel, and the faster the shutter speed we use the sooner we can get the exposure over and done with before the vibrations have any effect on the image.

We can employ ‘mirror up shooting’ as a technique to combat these vibrations; by lifting the mirror and then pausing to give the vibrations time to decay; and we could engage the lens VR too, as with the 3rd shot. Collectively there has been another significant jump in overall sharpness of shot 3; though frankly the VR contribution is minimal.

I’m not a very big fan of VR !

In shot 4 you might get some idea why I’m no fan of VR. Everything is the same as shot 3 except that the VR is OFF, and we’ve added a 3lb sandbag on top of the lens. This does the same job as hand holding the lens – it kills the vibrations stone dead.

When you are shooting landscapes with much longer exposures/shutter speeds THE ONLY way to work is tripod plus mirror up shooting AND if you can stand to carry the weight, a good heavy sand bag!

Shot 4 would have been just as sharp if the shutter had been open for 20 seconds, just as long as there was no movement at all in the subject AND there was no ground vibration from a passing heavy goods train (there’s a rail track between the camera and the subject!).

For general tripod shooting of fairly static subjects I was always confident of sharp shots on the D3 (12Mb) at 2x focal length.

But since moving to a 16Mp D4 I’ve now found that sometimes this let’s me down, and that 2.5x focal length is a safer minimum to use.

But that’s nothing compared to what some medium format shooters have told me; where they can still detect the effects of vibration on super high resolution backs such as the IQ180 etc at as much as 5x focal length – and that’s with wide angle landscape style lenses!

So, overall my advice is to ALWAYS push for the highest shutter speed you can possibly obtain from the lighting conditions available.

Where this isn’t possible you really do need to perfect the skill of hand holding – once mastered you’ll be amazed at just how slow a shutter speed you can use WITHOUT employing the VR system (VR/IS often causes far more problems than it would apparently solve).

For long lens shooters the technique of killing vibration at low shutter speeds when the gear is mounted on a tripod is CRITICAL, because without it, the images will suffer just because of the tripod!

The remedy is simple – it’s what your left arm is for.

So, to recap:

If you shot without a tripod, the physical act of hand holding – properly – has a tendency to negate internal system vibrations caused by mirror slap etc just because your physical mass is in direct contact with the camera and lens, and so “damps” the vibrations.
If you shoot without a tripod you need to ensure that you are using a shutter speed fast enough to negate camera shake.
If you shoot without a tripod you need to ensure that you are using a shutter speed fast enough to FREEZE the action/movement of your subject.

Camera Shake and STUPID VR!

Now I’m going to have to say at the outset that this is only my opinion, and that this is pointed at Nikons VR system, and I don’t strictly know if Canons IS system works on the same math.

And this is not relevant to sensor-based stabilization, only the ‘in the lens’ type of VR.

The mechanics of how it works are somewhat irrelevant, but what is important is its working methodology.

Nikon VR works at a frequency of 1000Hz.

What is a “hertz”? Well 1Hz = 1 full frequency cycle per second. So 1000Hz = 1000 cycles per second, and each cycle is 1/1000th sec in duration.

Full cycle sine wave showing 1,0.5 & 0.25 cycles.

Now then, here’s the thing. The VR unit is measuring the angular momentum of the lens movement at a rate of 1000 times per second. So in other words it is “sampling” movement every 1/1000th of a second and attempting to compensate for that movement.

But Nyquist-Shannon sampling theory – if you’re up for some mind-warping click HERE – says that effective sampling can only be achieved at half the working frequency – 500 cycles per second.

What is the time duration of one cycle at a frequency of 500Hz? That’s right – 1/500th sec.

So basically, for normal photography, VR ceases to be of any real use at any shutter speed faster than 1/500th.

Remember shot 3 with the 300mm f2.8 earlier – I said the VR contribution at 1/640th was minimal? Now you know why I said it!

Looking again at the frequency diagram above, we may get a fairly useful sample at 1/4 working frequency – 1/250th sec; but other than that my personal feelings about VR is that it’s junk – under normal circumstances it should be turned OFF.

What circumstances do I class as abnormal? Sitting on the floor of a heli doing ariel shots out of the open door springs to mind.

If you are working in an environment where something is vibrating YOU while you hand hold the camera then VR comes into its own.

But if it’s YOU doing the vibrating/shaking then it’s not going to help you very much in reality.

Yes, it looks good when you try it in the shop, and the sales twat tells you it’ll buy you three extra stops in shutter speed so now you can get shake-free shots at 1/10th of a second.

But unless you are photographing an anaesthetized Sloth or a statue, that 1/10th sec shutter speed is about as much use to you as a hole in the head. VR/IS only stabilizes the lens image – it doesn’t freeze time and stop a bird from flapping its wings, or indeed a brides veil from billowing in the breeze.

Don’t get me wrong; I’m not saying VR/IS is a total waste of time in ALL circumstances. But I am saying that it’s a tool that should only be deployed when you need it, and YOU need to understand WHEN that time is; AND you need to be aware that it can cause major image problems if you use it in the wrong situation.

Become a patron from as little as $1 per month, and help me produce more free content.

Patrons gain access to a variety of FREE rewards, discounts and bonuses.

In Conclusion

1/2000th sec is sufficient to pretty much freeze the forward motion of this eagle, but not the downward motion of the primary feathers.

This rather crappy shot of a White-tailed eagle might give you food for thought, especially if compared with the Red Kite at the start of the post.

The primary feathers are soft because we’ve run out of depth of field. But, notice the motion blur on them too? Even though 1/2000th sec in conjunction with a good panning technique is ample to freeze the forward motion of the bird, that same 1/2000th sec is NOT fast enough to freeze the speed of the descending primary feathers on the end of that 4 foot lever called a wing.

Even though your subject as a whole might be still for 1/60th sec or longer, unless it’s dead, some small part of it will move. The larger the subject is in the frame then more apparent that movement will be.

Getting good sharp shots without motion blur in part of the subject, or camera shake and system vibration screwing up the entire image is easy; as long as you understand the basics – and your best tool to help you on your way is SHUTTER SPEED.

A tack sharp shot without blur but full of high iso noise is vastly superior to a noiseless shot full of blur and vibration artefacting.

Unless it’s done deliberately of course – “H-arty Farty” as my mate Ole Martin Dahle calls it!

Become a patron from as little as $1 per month, and help me produce more free content.

Patrons gain access to a variety of FREE rewards, discounts and bonuses.

Nikon D4S

Posted on February 25, 2014 by Andrew Astbury

The new Nikon D4S announced today

Nikon D4S left & D4 right

Well, that’s about right, my sexy Nikon D4 is officially out of date, and thanks to the Nikon D4S I’ve just lost a grand off the resale value of my camera – cheers chaps…..

Is Uncle Andy stressed at all about being kitted out with yesterdays gear?

Nope, not really.

So what’s new on the Nikon D4S ?

Well there’s been a few ergonomic tweaks which basically mean nothing for starters.
Seemingly dispelled are the rumours that it would have a higher Mp count – apparently this stays the same at 16.2Mp.
I was expecting some major change in AF but no, they’ve kept the venerable Multi-Cam 3500FX system.
New sensor design.
BUT – they’ve changed the image processor to Expeed 4 from Expeed 3.
AND – they’ve changed the battery from EN-EL18 to an EN-EL18a.

Bare in mind all I’m going on is the web – perish the thought that Nikon would ever think my opinion worthy of note and ACTUALLY SEND ME ONE.

Other changes:

A new Group Area AF mode – which from my own photography PoV is fairly meaningless, seeing as we already have 9 point dynamic AF – I can’t see it’ll make much difference. Plus, the Group AF mode always focusses on the nearest point – something you rarely want the camera to do!
6 possible white balance presets as opposed to 3 on the D4 – I jam all my cameras into Cloudy B1 custom WB and leave them there – so this improvement isn’t worth jumping up and down about either.
Fairly gimmicky S Raw
Spot White Balance

On the storage front most reports say that the D4S carries over the D4 crazy arrangement of 1x CF plus 1x XQD.

My Basic Thoughts:

New Sensor – well the benefits can’t been seen by yours truly until I see a few RAW files from it – preferably taken by myself.

I’m glad they’ve kept it to 16.2Mp – if you crunch the numbers this is the optimum Mp count for an FX sensor – as Canon worked out aeons ago with the 1DsMk2; but then joined the stupid Mp race.

Image Processor changes – well, it’s reportedly 30% faster than the Expeed 3, which basically means that the D4S fires off images to storage 30% faster.

Now I can go out with the D4 and shoot getting on for 100 uncompressed 14bit RAW files in one continuous burst at 8 or 9 fps – do I want to chew through my storage any faster? NO!

The Expeed 4 gives better high ISO performance?

Well perhaps it does, but I look at it this way. If light is so damn low that you need to shoot at crackpot ISO numbers then you can say one thing – the light is crap.

If the light is crap then the image will look like crap – it’s just that with the Expeed 4 it’ll be slightly less noisy crap.

If I can pull 1/8000th sec at f7 or f8 at 3200ISO in half descent looking light using a D4 – which I do regularly – then why do I need a higher ISO capability?

The Red Squidger images you’ve seen in the previous blog articles are all 2000ISO and there is ZERO noise degradation – so again, why do I need more ISO capability.

Now if I was a ‘jobbing’ photo-jounalist, or I was embedded with the troops in Afghanistan or something of that ilk then I’d perhaps have a much different attitude.

But I’m not, and from my own perspective of wildlife & natural history photography these changes are of little interest to me – especially when they have a £5k price tag.

Battery Changes

There was always a persistent gripe about the battery life of the D4 EN-EL18 power cell – well, I’ve got two of them and have had no problems AT ALL with batteries running low.

I was REALLY annoyed that they switched from EN-EL4A D2/D3 style batteries – I’d got a handful of those already, and now when I go to Norway in June I’ve got to take 2 bloody chargers with me: yes the venerable D3 will be getting a summer holiday this year as second camera.

So, for me at least, the increased battery life of the new Nikon D4S 18a batteries is somewhat inconsequential – why do I want a battery that lasts longer than ‘for ever’ ??

Other Changes/Additions

I can’t see anything that excites me: spot white balance? Go and buy a Colour Checker Passport and do the job right – and that doesn’t cost £5k either (though they are a bit pricey).

Group Area AF – do me a favour (see above).

6 White Balance presets – what’s the point?

All of the above could be given away by Nikon as a firmware update for the D4 if they fancied being generous!

What I Would Have Got Excited About.

Twin UDMA 7 CF card slots and an XQD slot for dedicated video recording.

An improved AF module.

The ability to select ‘matched pairs’ of sensors – Canon offered this years ago and it was brilliant.

Internally recorded FX video of EXACTLY the same quality as that of a Canon 5D3, or at least the same quality as internal 1080p CROP.

AF mode selector back WHERE IT SHOULD BE!

Me being put in charge at Nikon!

In Conclusion

Do I want to buy one (even if I had the dough) – NO!

Do I wish I could afford one – NO!

Would I swap my D4 for a D4s – well of course I would.

Seriously though, I can just see an awful lot of people getting “hot under the collar” and stressing over this latest incarnation of this pro body from Nikon; but seriously, if you are then you need to just take a quiet step back and think about things calmly.

There is nothing – IMHO of course – on the D4S that warrants upgrading from the D4 – unless you have a penchant for spending your money that is.

But if you are still on a D3 or something older, and were thinking about buying a D4 – then hold off a while until the D4S in available; it’s makes better fiscal sense.

Become a patron from as little as $1 per month, and help me produce more free content.

Patrons gain access to a variety of FREE rewards, discounts and bonuses.

The Prospec 32Gb UDMA 7 Compact Flash Card from Calumet – review

The Way I Use Camera Storage Media

What Do The ‘Hieroglyphics’ All Mean?

Nikon Users

Conclusion

Footnote

Share this post:

Image Sharpness

Shameless Plug Number 1.

Understanding Canon & Nikon Autofocus

for

Bird in Flight Photography

Share this post:

Testing & Evaluation

Autofocus:

Autofocus Conclusion:

A Nikon Users Final Judgement on the 1Dx + 200-400mm f4 L IS USM

Please consider supporting this blog.

Share this post:

Share this post:

Speed Light Photography – part 1

Share this post:

Long Exposure & ND Filters

SENSOR TYPE

REALITY

It’s a Question of Time

Share this post:

Auto Focus Work Out

Auto Focus Choices

How Dynamic Area AF Works

Auto Focus Senor Types – Cross and Linear (line).

The Back Button Auto Focus Option

Conclusion

Share this post:

Trap Focus on the Nikon D4

Setup for D4 Trap Focus

Share this post:

Fast Shutter Speed – I need MORE LIGHT Barry!

Creative Slow Shutter Speed – getting rid of light.

Slow Shutter Rear Curtain Synch Flash

Shutter Speed and System Vibration

How Does System Vibration Effect an Image?

Camera Shake and STUPID VR!

In Conclusion

Share this post:

The new Nikon D4S announced today

My Basic Thoughts:

Battery Changes

Other Changes/Additions

What I Would Have Got Excited About.

In Conclusion

Share this post: