More ISO Settings Misinformation

More ISO Settings Misinformation

This WAS going to be a post about exposure…….!

But, this morning I was on the Facebook page of friend where I came across a link he’d shared to this page which makes a feature of this:

%name More ISO Settings Misinformation

Please Note: I’m “hot linking” this image so’s not to be accused of theft!

This style of schematic for the Exposure Triangle is years old and so is nothing new.

When using FILM the ISO value IS a measure of sensitivity to light – that of the film, in other words its SPEED.  Higher ISO film is more sensitive to light than lower ISO film, and the increased sensitivity brings about larger ‘grain’ in the image.

When we talk ‘digital photography’ however the ISO value HAS NOTHING TO WITH SENSITIVITY TO LIGHT – of anything inside your camera, including the damn sensor.

ISO in digital cameras is APPLIED GAIN. Applied ‘after the exposure has been made’..after the fact…after Elvis has left the freaking building!

Your sensors sensitivity to light is FIXED and dictated by the size of the photosites that make up the sensor – that is, the sensor pixel pitch.

People who persist in leading you guys into thinking that ISO controls sensor sensitivity should be shot, or better still strapped over the muzzle of an artillery piece……..

The article then goes on to advise the following pile of horse crap:

Recommended ISO settings:

  • ISO 100 or 200 for sunny and bright daylight 
  • ISO 400 ISO for cloudy days, or indoors 
  • ISO 800 for indoors (without a flash) 
  • ISO 1600+ for very low light situations 

WTF??? What year are we in – 2007??

And this pile of new 2017 junk is on a website dedicated to a certain camera manufacturer who’s cameras have produced superb images at ISO settings way higher than the parameters stated above for ages.

Take this shot from a Canon 1DX Mk1 – old tech/off-sensor ADCs etc:

FW1Q4333 600x400 More ISO Settings Misinformation

Canon 1DX Mark 1 ISO 10,000 1/8000th @ f7.1 – click for the full size image.

ISO settings are at the bottom of the pile when it comes to good action photography – the overriding importance at all times is SHUTTER SPEED and AF performance.

I don’t care about ‘ISO noise’ anywhere near as much as I care about focus and freezing the action, and neither should you guys.

What have the above and below shots got in common – apart from the wildlife category?

 D4R3440 More ISO Settings Misinformation

Nikon D4 – a meagre ISO 3200 1/8000th @ f7.1 – click for full size image.

1/8000th shutter speed and an aperture of 7.1 – aperture for DoF and shutter speed to freeze the action – stuff the ‘noise’.

And speaking of ‘noise’ – there isn’t anywhere near enough to screw the shot up for stock sale even at full size, and I’ll tell you again, noise hardly prints at all!

Here’s another ‘old tech’ Canon 1DX Mk1 shot:

GX2R4727 More ISO Settings Misinformation

And here’s where the rubber really meets the road – low light 4000ISO  1/200th @ f6.3 – click for full size image.

I don’t really want to wheel the same shots out over and over but don’t forget the Canon 5D Mk4 Great Tit at 10,000ISO or 1DX Mk2 Musk Ox at 16,000ISO either!

Don’t get me wrong, when I want maximum Dynamic Range I shoot at base ISO, but generally you’ll never find me shooting at any fixed ISO other than base; other than when shooting astro landscapes.  Everything else is Auto ISO.

So a fan website, in 2017, is basically telling you not to use the ISO speeds that I use all the damn time – and they are justifying that with bad information.

Please people, 90% plus of what you see on the web is total garbage, please don’t take it as gospel truth until you check with someone who actually knows what they are talking about.

Do I know what I’m talking about, well, only you can judge that one.  But everything I do tell you can be justified with full resolution images – not meaningless little jpegs on a web site.

Anyway, that’s it – rant over!

As ever, if you like the info in this post hit the subscribe button. Hop over to my YouTube channel and subscribe there too and if you are feeling generous then a couple of bucks donation via PayPal to tuition@wildlifeinpixels.net would be gratefully appreciated!

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Canon 16-35mm f2.8 Mk3

Canon 16-35mm f2.8 Mk3

D8E6995 1 400x400 Canon 16 35mm f2.8 Mk3

Wow, it’s a bit big!  That was the first thought I had when getting hold of this lens for the first time – I thought for a second the lovely Leanne at Calumet Manchester had given me 24-70 by mistake.

It’s longer, fatter in the barrel and somewhat heavier than its Mk2 predecessor – but is it any better?

I suppose I can be a bit more objective than most reviewers of this lens when it comes to Canon wide glass because I never use it!

Canon has always seemed to have a different ethos to that of Nikon and TPMs such as Zeiss when it comes to wide glass design.

For sports/photojournalism they have always functioned perfectly well because they are usually quite light, fast to use, versatile, cheap(ish) and adequately sharp for the job -and they’ve sold millions over the years…and rightly so.

But if you wanted a high resolution wide angle with good micro contrast and superb sharpness then, as a landscape photographer for example, you’d be struggling.

Low resolution, poor contrast, vignetting, axial and lateral chromatic aberration, extreme corner distortion and coma are typical faults with wide angle lenses across the board, but Canon wide glass has had more exemplars of these faults than most.

Don’t get me wrong, Nikon have produced some real ‘dogs’ too – just not quite as many!

Let’s face it, no Canon wide could slip into a line up of of Zeiss glass and go optically unnoticed.

When Nikon brought out the 14-24 f2.8 why did Novoflex start flogging mount adapters to Canon shooters?

The only folk who will argue with me are those that have never tried Nikon or Zeiss.

As Canon WA glass goes, the 16-35mm f2.8 Mk2 does an OK job with landscapes, and for the most part produces results very much like the Nikon 24-70mm f2.8 when both lenses are shot at around 26mm to 32mm, but it leaves more than a bit to be desired when being shot wide open.

Its worst fault for me, shooting wide open, is the vile level of COMA.  There’s been many a wide-field astro shot consigned to the bin because if it.

D8E7003 400x400 Canon 16 35mm f2.8 Mk3

Canon 16-35mm f2.8 Mk3 with the Mk2 on the right.

So, is the new Canon 16-35mm f2.8 Mk3 an improvement – it needs to be for the price.

D8E6997 1 400x400 Canon 16 35mm f2.8 Mk3

Canon 16-35mm f2.8 Mk3 with the Mk2 on the right.

The Canon 16-35mm f2.8 Mk3 takes the same 82mm screw mount filters.

There is a newly re-designed lens hood.

Typical of this style of wide zoom, even though its an internal FOCUS lens, like its predecessor, it’s not strictly an internal ZOOM.  The front element moves in and out as the zoom ring is rotated, being furthest forward at 16mm, furthest back at around 26mm and then creeping forward again as we go to 35mm.

Designs like this have ‘compromise’ stamped all over them.  The legendary Nikon 14-24mm does the same sort of external zooming with its front element group, but is furthest forward at 14mm and furthest back at 24mm.  The Nikon is a super wide zoom while the Canon is a super wide to standard wide zoom.  Standard wide angle requires a different element design and layout – so COMPROMISE!

This moving front element makes all lenses designed this way ‘suckers and blowers’ so the cautious among you might want to put one of those lens protect filters on the front.

If you do, then PLEASE, don’t pay thousands for a lens and then be a cheapskate.  You lose light with every air/glass surface you place in the optical pathway.  And a lot of these filters SAY they are optically correct when they are most definitely NOT.  The finest lens in the world turns into a turd if you stick a cheap filter on it.

D8E7011 1 400x400 Canon 16 35mm f2.8 Mk3

Canon 16-35mm f2.8 Mk3 with the Mk2 on the right.

So let’s take a look at vignetting.  We’ll do that in two ways.

Firstly, let’s see how the vignetting at f2.8 changes with focal length, with the Mk2 on the left, and the Mk3 on the right:

Mk3f2.8FLVig 246x400 Canon 16 35mm f2.8 Mk3

Vignetting of the Canon 16-35mm f2.8 Mk II & III at various focal lengths at a constant f2.8

Next, let’s stay at 16mm focal length on both lenses and look at the vignetting through the aperture range:

16mmVgTest 1 407x900 Canon 16 35mm f2.8 Mk3

Vignetting of the Canon 16-35mm f2.8 Mk II & III at various apertures and a constant 16mm focal length.

Now these vignette results didn’t leave me in a state of shock and awe in the slightest.

You need to view the images at 100% to see the subtle improvements in the Canon 16-35mm f2.8 Mk3.

In the first test – maximum aperture vs focal length, the new variant looks equal to or slightly worse than the Mk 2 at 16mm.

But things begin to improve a bit once we are getting towards 24mm.

On the second test – 16mm vs aperture range, again we see the awful maximum aperture vignetting compared to its predecessor.

From f5.6 to f16 it’s perhaps a sliver better than the Mk2. But, notice that the images are a bit brighter.  This is most likely to do with the improvements made to the multi-coatings.

Canon 16-35mm f2.8 Mk3 vs Mk2 Image Comparisons

Let me begin by saying this – 16mm on the Mk3 is NOT the same 16mm that the Mk2 has!

1D9A6348 Canon 16 35mm f2.8 Mk3 1D9A6347 Canon 16 35mm f2.8 Mk3

Mouse over the slider – see what I mean?

Both shots are 16mm @ f11 on the Canon 5DMk4.  The camera was locked down on my heavy Gitzo, and the camera was triggered with a Canon TC-80N3 – in other words NOTHING moved!

The images have not been adjusted in any way – no lens correction profiles – as shot.

Notice the Mk3 image has greater ‘contrast’ and is less flat-looking?

Okay, so let’s look at the ubiquitous ‘brick wall’ test.

We are doing shots on the 5DMk4 using both Mk2 and Mk3 lens variants.

  • at 200ISO
  • at f2.8, f5.6 and f11
  • at 16mm, 25mm and 35mm
  • at a fixed ‘Cloudy B1’ manual camera white balance
  • manual focusing
  • the camera has been re-focused using x10 live view between each frame.
Screen Shot 2016 12 30 at 13.03.17 600x375 Canon 16 35mm f2.8 Mk3

IMPORTANT – CLICK IMAGE to view at full size in new window.

Screen Shot 2016 12 30 at 14.24.56 600x375 Canon 16 35mm f2.8 Mk3

IMPORTANT – CLICK IMAGE to view at full size in new window. 16mm @ f5.6

Screen Shot 2016 12 30 at 14.27.56 600x375 Canon 16 35mm f2.8 Mk3

IMPORTANT – CLICK IMAGE to view at full size in new window. 16mm @ f11

The above screen grabs give you a great ‘feel’ for all the differences in contrast and lens colour cast between the Mk2 and new Mk3 variants – these are quite significant.  Even more so when when you look at the vignetting, distortion and AoV differences.

Moving on to the full resolution comparisons:

Again, no adjustments at all other than Lightroom standard profile sharpening, and we are looking at the frame centers at 1:1 ratio:

Screen Shot 2016 12 30 at 13.19.28 600x375 Canon 16 35mm f2.8 Mk3

IMPORTANT – CLICK IMAGE to view at full size in new window. 16mm @ f2.8

At 16mm @ f2.8 (above) the Canon 16-35mm f2.8 Mk3 is noticeably sharper than its predecessor.

Screen Shot 2016 12 30 at 13.31.01 600x375 Canon 16 35mm f2.8 Mk3

IMPORTANT – CLICK IMAGE to view at full size in new window. 16mm @ f5.6

Stopping down to f5.6 @ 16mm yields a better sharpness on the older Mk2 variant.  Is there a tiny bit of improved sharpness on the new Mk3 – perhaps.

Screen Shot 2016 12 30 at 13.42.08 600x375 Canon 16 35mm f2.8 Mk3

IMPORTANT – CLICK IMAGE to view at full size in new window. 16mm @ f11

Now at 16mm @ f11 both lenses seem ever so slightly less sharp.  But that is not down to diffraction as you’ll see later with the 25mm and 35mm tests.  I could be an error on my part when focusing, but for me to make the same mistake on two different lenses is a bit of a long shot.  I’ve re-shot and got the same result – methinks it might have something to do with that ‘compromise’ I mentioned earlier on….or, it could be me!

Moving from 16mm to 25mm and 35mm:

Screen Shot 2016 12 30 at 14.32.48 600x375 Canon 16 35mm f2.8 Mk3

IMPORTANT – CLICK IMAGE to view at full size in new window. 25mm @ f2.8

Screen Shot 2016 12 30 at 14.33.04 600x375 Canon 16 35mm f2.8 Mk3

IMPORTANT – CLICK IMAGE to view at full size in new window. 25mm @ f2.8

Screen Shot 2016 12 30 at 14.34.28 600x375 Canon 16 35mm f2.8 Mk3

IMPORTANT – CLICK IMAGE to view at full size in new window. 25mm @ f5.6

Screen Shot 2016 12 30 at 14.34.47 600x375 Canon 16 35mm f2.8 Mk3

IMPORTANT – CLICK IMAGE to view at full size in new window. 25mm @ f5.6

Screen Shot 2016 12 30 at 14.35.32 600x375 Canon 16 35mm f2.8 Mk3

IMPORTANT – CLICK IMAGE to view at full size in new window. 25mm @ f11

Screen Shot 2016 12 30 at 14.35.46 600x375 Canon 16 35mm f2.8 Mk3

IMPORTANT – CLICK IMAGE to view at full size in new window. 25mm @ f11

Screen Shot 2016 12 30 at 14.36.28 600x375 Canon 16 35mm f2.8 Mk3

IMPORTANT – CLICK IMAGE to view at full size in new window. 35mm @ f2.8

Screen Shot 2016 12 30 at 14.36.44 600x375 Canon 16 35mm f2.8 Mk3

IMPORTANT – CLICK IMAGE to view at full size in new window. 35mm @ f2.8

Screen Shot 2016 12 30 at 14.37.24 600x375 Canon 16 35mm f2.8 Mk3

IMPORTANT – CLICK IMAGE to view at full size in new window. 35mm @ f5.6

Screen Shot 2016 12 30 at 14.37.38 600x375 Canon 16 35mm f2.8 Mk3

IMPORTANT – CLICK IMAGE to view at full size in new window. 35mm @ f5.6

Screen Shot 2016 12 30 at 14.38.21 600x375 Canon 16 35mm f2.8 Mk3

IMPORTANT – CLICK IMAGE to view at full size in new window. 35mm @ f11

Screen Shot 2016 12 30 at 14.38.36 600x375 Canon 16 35mm f2.8 Mk3

IMPORTANT – CLICK IMAGE to view at full size in new window. 35mm @ f11

Make sure you have viewed all the above screen shots at full resolution.

Okay, so we have visually covered iteration comparisons for the Canon 16-35mm f2.8 Mk3 and its predecessor in terms of distortion, vignetting, field/angle of view and sharpness.

In terms of stopped-down sharpness, on the Canon 5DMk4 at least, I’d expect to get into the realms of aperture diffraction around f14 to f16.

Wide open the Mk3 version stomps all over the Mk2, and I think it stays ahead through to at least f11 across the entire focal length zoom range.

Chromatic Aberration

The Mk2 16-35 f2.8 has a somewhat noticeable chromatic aberration problem, so how does the new Mk3 version measure up in comparison – both shots are 16mm @ f11:

1D9A6347 Edit 2 600x400 Canon 16 35mm f2.8 Mk3

Click the image and a full size jpeg (80% quality) will open in a new window.

1D9A6348 Edit 2 600x400 Canon 16 35mm f2.8 Mk3

Click the image and a full size jpeg (80% quality) will open in a new window.

Compare the lamp post on the right and the window and alarm box on the left of the shots.

Though still present, chromatic aberration is much reduced on the new Canon 16-35mm f2.8 Mk3.  Along the middle axes of the image – especially the horizontal – there have been big improvements.

The Lightroom ‘remove chromatic aberration’ function cleans the raw file up beautifully without having to go anywhere near the manual corrections – just tick the checkbox. But doing the same to a Mk2 image usually leaves vestiges of both red and green fringing at the frame edges at 16mm.

Coma Test:

What’s Coma? It’s a lens design flaw which renders ‘tails’ and ‘wings’ on off-axis points of light.

And here is a shining example, courtesy of the Mk2 16-35:

J6Q7329 Canon 16 35mm f2.8 Mk3

Coma on the Canon 16-35mm f2.8 Mk2 variant.

Mmmm…yummy!

It’s not exactly the best time of year for Milky Way astro shots here in the UK – New Year as it is.  But we ventured out at midnight the other night just to test this Mk3 version of the lens.

The area is fairly local and surrounded on all sides by huge light polution but it served the purpose of the test.

Shooting wide open f2.8 @ 6400ISO, stacking 8 shots done in quick succession here’s the truth about the coma on the new Mk3 16-35mm variant:

1D9A6327 18 600x400 Canon 16 35mm f2.8 Mk3

Click the image and a full size jpeg (80% quality) will open in a new window.

It’s not the best astro you’ll ever see, but it does show that the coma is still there, but it’s a lot less intrusive.

In Conclusion

So there we have it – the new Canon 16-35mm f2.8 Mk3.

Is it better than it’s Mk2 predecessor?  Well yes, it is – and in pretty much every aspect I’d say.

The vignetting at 16mm f2.8 is quite strong – nearly 4 stops darker than the image center.  This WILL cause you problems if you have peripheral deep shadow areas, as even on the 5DMk4, pulling 4 stops will make the shadow areas go a bit noisy.

I also think that 16mm is now more like 18mm, but what’s a couple of mills between friends ehh!

Would I buy one? Well, that depends.

If I had a Mk2 variant and needed the lens format then I would be looking to trade in immediately.

Wedding, street, sports/photojournalism and events photographers would be mad if they didn’t have one of these in their bag. And I think wildlife photographers would benefit as well – I reckon it would be perfect on the 1DX Mk2 for just about anything.

Not being a Canon shooter for anything below a 200-400 I won’t be putting it on my ‘wants’ list at all, but if you are ‘Canon-only’ then I strongly recommend you have a look at this lens.

As for landscapes and wide field astro, erm…..let’s just say there’s more than one way to skin a cat, and some are better than others.  Having said that, if you are a landscape shooter with a Mk2 variant and you can’t afford/ just don’t want a plethora of glass for specific tasks then it’s a big improvement on what you’ve already got.

Where to buy this lens in the UK – buy it here Calumet Photographic

Many thanks to Reece Piper, Leanne and Richard from Calumet for loaning this lens for the purposes of review.

And a big thanks to June Lown for the loan of the Mk2 to make the comparison.

17.5 hours that’s taken – Jesus, it’s like having a full-time job!  If this review has been useful to you then please consider chucking me a small donation – or a big one if you are that way inclined!

Many thanks to the handful of readers who contributed over the last week or so – you’ve done your bit and I’m eternally grateful to you.

Happy New Year everyone!

Camera ISO Settings

The Truth About ISO

Back in the days of ‘wet photography’, we had rolls and sheets of film that carried various ISO/ASA/DIN numbers.

ISO stands for International Standards Organisation

ASA stands for American Standards Association

DIN – well, that’s ‘Deutsches Institut für Normung’ or German Institute for Standardisation

ISO and ASA were basically identical values, and DIN = (log10)ISO x10 +1, so ASA/ISO 100 equated to DIN 21….nope, I’m not going to say anything!

These numbers were the film ‘speed’ values.  Film speed was critical to exposure metering as it specified the film sensitivity to light.  Metering a scene properly at the correct ISO/ASA/DIN gave us an overall exposure value that ensured the film got the correct ‘dose’ of light from the shutter speed and aperture combination.

Low ISO/ASA/DIN values meant the film was LESS sensitive to light (SLOW FILM) and high values meant MORE sensitivity to light (FAST FILM).

Ilford Pan F was a very slow mono negative film at ASA 50, while Ilford HP5 was a fast 400 ASA mono negative film.

The other characteristic of film speed was ‘grain’.  Correctly exposed, Pan F was extremely fine grained, whereas correctly exposed HP5 was ‘visibly grainy’ on an 8×10 print.

Another Ilford mono negative film I used a lot was FP4.  The stated ASA for this film was 125ASA/ISO, but I always rated it (set the meter ASA speed dial) to 100ASA on my 35mm Canon A1 and F1 (yup, you read that right!) because they both slightly over-metered most scenes.

If we needed to shoot at 1/1000th and f8 but 100ASA only gave us 1/250th at f8 we would switch to 400ASA film – two stops greater sensitivity to light means we can take a shutter speed two stops shorter for the same aperture and thus get our required 1/1000th sec.

But, what if we were already set up with 400ASA film, but the meter (set at 400ASA) was only giving us 1/250th?

Prior to the release of films like Delta 1600/3200 we would put a fresh roll of 400ASA film in the camera and set the meter to a whopping 1600ASA! We would deliberately UNDER EXPOSE Ilford HP5 or Kodak Tri-X by 2 stops to give us our required 1/1000th at f8.

The two stops underexposed film would then be ‘push processed’, which basically meant it was given a longer time in the developer.  This ‘push processing’ always gave us a grainy image, because of the manner in which photographic chemistry worked.

And just to confuse you even more, very occasionally a situation might arise where we would over expose film and ‘pull process’ it – but that’s another story.

We are not here for a history lesson, but the point you need to understand is this – we had a camera body into which we inserted various sensitivities of film, and that sometimes those sensitivities were chemically manipulated in processing.

That Was Then, This Is Now!

ISO/ASA/DIN was SENSITIVITY of FILM.

It is NOT SENSITIVITY of your DSLR SENSOR….!!! Understand that once and for all!

The sensitivity of your sensor IS FIXED.

It is set in Silicon when the sensor is manufactured.  Just like the sensitivity of Kodak Tri-X Pan was ‘fixed’ at 400ASA/ISO when it was made at the factory.

How is the sensitivity of a digital sensor fixed?  By the SIZE of the individual PHOTOSITES on the sensor.

Larger photosites will gather more photons from a given exposure than small ones – it’s that simple.

The greater the number of photons captured means that the output signal from a larger photosite is GREATER than the output signal from a smaller photosite for the same exposure value (EV being a combination shutter speed and aperture/f number).

All sensors have a base level of noise – we can refer to this as the sensor ‘noise floor’.

This noise floor is an amalgamation of the noise floors of each photosite on the sensor.

But the noise floor of each photosite on the sensor is masked/obscured by the photosite signal output; therefore the greater the signal, the larger the signal to noise (S/N) ratio is said to be.

In general, larger photosites yield a higher S/N ratio than smaller ones given the same exposure.

This is why the Nikon D3 had such success being full frame but just over 12 megapixels, and it’s the reason that some of us don’t get overly excited about seeing more megapixels being crammed into our 36mm x 24mm sensors.

Anyway, the total output from a photosite contains both signal and noise floor, and the signal component can be thought of as ‘gain’ over the noise floor – natural gain.

As manufacturers put more megapixels on our sensors this natural gain DECREASES because the photosites get SMALLER – they have to in order to fit more of them into the finite sensor area.

Natural gain CAN be brought back in certain sensor designs by manipulating the design of the micro lenses that sit on top of the individual photosites. Re-design of these micro lenses to ‘suck in’ more tangential photons – rather like putting a funnel in a bottle to make filling it easier and more efficient.

There is a brilliantly simple illustration of how a sensor fits into the general scheme of things, courtesy of digital camera world:

%name Camera ISO Settings

The main item of note in this image is perhaps not quite so obvious, but it’s the boundary between the analogue and digital parts of the system.

We have 3 component arrays forward of this boundary:

  1. Mosaic Filter including Micro Lenses & Moire filter if fitted.
  2. Sensor Array of Photosites – these suck in photons and release proportional electrons/charge.
  3. Analogue Electronics – this holds the charge record of the photosite output.

Everything forward of the Analogue/Digital Converter – ADC – is just that, analogue! And the variety of attributes that a manufacturer puts on the sensor forward of this boundary can be thought of mostly as modifying/enhancing natural gain.

So What About My ISO Control Settings Andy?

All sensors have a BASE ISO. In other words they have an ISO sensitivity/speed rating just like film!  And as I said before THIS IS A FIXED VALUE.

The base ISO of a sensor photosite array can be defined as that ISO setting that yields the best dynamic range across the whole array, and it is the ISO setting that carries NO internal amplification.

Your chosen ISO setting has absolutely ZERO effect on what happens forward of the Analogue/Digital boundary – NONE.

So, all those idiots who tell you that ISO effects/governs exposure are WRONG – it has nothing to do with it for the simple reason that ISO effecting sensor sensitivity is a total misconception….end of!

Now I’ll bet that’s going to set off a whole raft of negative comments and arguments – and they will all be wrong, because they don’t know what they’re talking about!

The ‘digital side’ of the boundary is where all the ‘voodoo’ happens, and it’s where your ISO settings come into play.

At the end of an exposure the Analogue Digital Converter, or ADC, comes along and makes a ‘count’ of the contents of the ‘analogue electronics’ mosaic (as Digital Camera World like to call it – nice and unambiguous!).

Remember, it’s counting/measuring TOTAL OUTPUT from each photosite – and that comprises both signal and noise floor outputs.

iso1 900x900 Camera ISO Settings

If the exposure has been carried out at ‘base ISO’ then we have the maximum S/N ratio, as in column 1.

However, if we increase our ISO setting above ‘base’ then the total sensor array output looks like column 2.  We have in effect UNDER EXPOSED the shot, resulting in a reduced signal.  But we have the same value for the noise floor, so we have a lower S/N ratio.

In principal, the ADC cannot discriminate between noise floor and signal outputs, and so all it sees in one output value for each photosite.

At base ISO this isn’t a problem, but once we begin to shoot at ISO settings above base, under exposing in other words, the cameras internal image processors apply gain to boost the output values handed to it by the ADC.

Yes, this boosts the signal output, but it also amplifies the noise floor component of the signal at the same time – hence that perennial problem we all like to call ‘high ISO noise’.

So your ISO control behaves in exactly the same way as the ‘gain switch’ on a CB or long wave radio, or indeed the db gain on a microphone – ISO is just applied gain.

Things You Should Know

My first digital camera had a CCD (charge coupled device) sensor, it was made by Fuji and it cost a bloody fortune.

Cameras today for the most part use CMOS (complimentary metal oxide semi-conductor) sensors.

  • CCD sensors create high-quality, low-noise images.
  • CMOS sensors, traditionally, are more susceptible to noise.
  • Because each photosite on a CMOS sensor has a series of transistors located next to it, the light sensitivity of a CMOS chip tends to be lower. Many of the photons striking the sensory photosite array hit the transistors instead of the photosites.  This is where the newer micro lens designs come in handy.
  • A CMOS sensor consumes less power. CCD sensors can consume up to 100 times more power than an equivalent CMOS sensor.
  • CMOS chips can be produced easily, making them cheaper to manufacture than CCD sensors.

Basic CMOS tech has changed very little over the years – by that I’m referring to the actual ‘sensing’ bit of the sensor.  Yes, the individual photosites are now manufactured with more precision and consistency, but the basic methodology is pretty much ‘same as it ever was’.

But what HAS changed are the bits they stick in front of it – most notably micro-lens design; and the stuff that goes behind it, the ADC and image processors (IPs).

The ADC used to be 12 bit, now they are 14 bit on most digital cameras, and even 16 bit on some.  Increasing the bit depth accuracy in the ADC means it can detect smaller variations in output signal values between adjacent photosites.

As long as the ‘bits’ that come after the ADC can handle these extended values then the result can extend the cameras dynamic range.

But the ADC and IPs are firmware based in their operation, and so when you turn your ISO above base you are relying on a set of algorithms to handle the business of compensating for your under exposure.

All this takes place AFTER the shutter has closed – so again, ISO settings have less than nothing to do with the exposure of the image; said exposure has been made and finished with before any ISO applied gain occurs.

For a camera to be revolutionary in terms of high ISO image quality it must deliver a lower noise floor than its predecessor whilst maintaining or bettering its predecessors low ISO performance in terms of noise and dynamic range.

This where Nikon have screwed their own pooch with the D5. At ISOs below 3200 it has poorer IQ and narrower dynamic range than either the D4 or 4S.  Perhaps some of this problem could be due to the sensor photosite pitch (diameter) of 6.45 microns compared to the D4/4S of 7.30 microns – but I think it’s mostly due to poor ADC and S/N firmware; which of course can be corrected in the future.

Can I Get More Photons Onto My Sensor Andy?

You can get more photons onto your sensor by changing to a lens that lets in more light.

You might now by thinking that I mean switching glass based on a lower f-number or f-stop.

If so you’re half right.  I’m actually talking about t-stops.

The f-number of a lens is basically an expression of the relationship between maximum aperture diameter and focal length, and is an indication of the amount of light the lens lets in.

T-stops are slightly different. They are a direct indicator of how much light is transmitted by the lens – in other words how much light is actually being allowed to leave the rear element.

We could have two lenses of identical focal length and f-number, but one contains 17 lens elements and the other only 13. Assuming the glass and any coatings are of equal quality then the lens with fewer elements will have a higher transmission value and therefore lower T-number.

As an example, the Canon 85mm f1.2 actually has a t-number of 1.4, and so it’s letting in pretty much HALF a stop less light than you might think it is.

In Conclusion

I’ve deliberately not embellished this post with lots of images taken at high ISO – I’ve posted and published enough of those in the past.

I’ve given you this information so that you can digest it and hopefully understand more about how your camera works and what’s going on.  Only by understanding how something works can you deploy or use it to your best advantage.

I regularly take, market and sell images taken at ISO speeds that a lot of folk wouldn’t go anywhere near – even when they are using the same camera as me.

The sole reason I opt for high ISO settings is to obtain very fast shutter speeds with big glass in order to freeze action, especially of subjects close to the camera.  You can freeze very little action with a 500mm lens using speeds in the hundredths of a second.

Picture buyers love frozen high speed action and they don’t mind some noise if the shot is a bit special. Noise doesn’t look anywhere near as severe in a print as it does on your monitor either, so high ISO values are nothing to shy away from – especially if to do so would be at the expense of the ‘shot of a lifetime’.

Workshop Report and Canon 1DX Mk2 first thoughts

Workshop Report and Canon 1DX Mk2 first thoughts

September 9th to 16th, Norway Musk Ox and Sea Eagles.

DSC 9620 Workshop Report and Canon 1DX Mk2 first thoughts

Left to Right: Mark Davies, Sigbjorn Frengen (our specialist Musk Ox guide for Dovrefjell), “Some Bearded Fat Git”, Mohamed Al Ashkar, Paul Atkins and Malcolm Clayton.

All four clients have been on numerous trips to Norway before, but for everyone, including myself, it was our first time in the Dovrefjell–Sunndalsfjella National Park and the magnificent Musk Ox that call the place home.

Firstly, I have to say a massive thank you to our specialist guide for the Musk Ox, Sigbjorn Frengen.

He’s a superb guide, the font of all ecological knowledge, has a driving passion for what he does, is as fit as the proverbial Butchers Dog, and is only in his mid 20’s.  He took guiding a bunch of geriatric old farts like us well in his stride; totally oblivious to the fact that we were all mighty jealous of his youth and fitness and secretly wanted to kill him for it!

And yes, I immediately booked him for the Dovrefjell part of my September 2017 workshop!

Musk Ox are animals not to be trifled with – they may look very benign but they weigh in at between 400 and 600 kilograms and can outrun Usain Bolt with very little effort.  They are quick to temper, but the signs of the oncoming rage are subtle and difficult to spot even at 60-70 metres. Subtle head-shaking and snorting are the main give-aways that you are causing some displeasure:

11I1683 2 600x400 Workshop Report and Canon 1DX Mk2 first thoughts

A lone female Musk Ox snorts her displeasure at the presence of the photographer. She wants to rejoin the herd but the camera is in her way, so she blows mucus out of nose as a sign of annoyance.  Canon 1DX Mk2 + 200-400 @ 560mm 1/2500th sec @ f7.1 and 16,000ISO – YES SIXTEEN THOUSAND!

 

The above image shows brilliantly my other main task for the week – testing the Canon 1DX mark 2.

Most people know me as a Nikon shooter, and that I have a love-hate relationship with Canon – yes, I’m a troubled person!

I’ve waxed lyrical about the Canon 200-400 f4 many times on this blog and elsewhere, and the fact that I consider the Canon 61 point Reticular AF System to be the best on the planet.

You will also know that I loathe the sensor output of the original 1DX, and Canons daft refusal to give us the Uncompressed RAW Recording capability – spoilt see, Nikon user!!

I managed to get a couple of hours on the Canon 1DX Mk2 back in July and promptly set about testing the improved AF algorithms – by jingo was I impressed.  I was getting 40% less dropped shots on the Canon 1DX Mk2 at 10 frames per second than I was used to at 6 frames per second on the Mk1.

And as for the sensor output in general, the shadows adjustment latitude and high ISO performance – well, it was a revelation.

The Musk Ox above (click the image to view the full rez) has virtually ZERO noise reduction on it – none in post, and LOW on the in-camera High ISO NR menu setting.

11I3358 600x400 Workshop Report and Canon 1DX Mk2 first thoughts

A baby Musk Ox lying by its mothers side on a soft bed of lichen, Erica and rare alpine plants. ISO 2500, 200-400 @ 560mm, 1/2500@f7.1

Why use such a high shutter speed Andy?

It’s brain-in-gear time folks – breezy conditions, lowish light levels, hair on the subject that’s over 1metre long, and wispy grass stems – all these move way faster than the bulky Musk Ox itself – under peaceful circumstances of course!. If these little tiny details suffer with motion blur it ruins the image – provided you have a sensor that can ‘deliver the goods’ at the resultant ISO-stupid.

I’m also shooting hand-held off the knee, with and effective 560mm angle of view on a 20Meg+ sensor, so I’ll need at least 1/1600th to combat the shakes, and I am indeed ‘testing’ a camera, so shooting at sub 1600ISO is not doing the job.

I’m using ‘spot AF’ and partial metering, and my AF point is bang in the middle of the point pattern.

This all neatly brings me to my first problem with the Canon 1DX Mk2 – or at least the one I was using – look at this image from a few frames before:

11I3352 600x400 Workshop Report and Canon 1DX Mk2 first thoughts

A baby Musk Ox lying by its mothers side on a soft bed of lichen, Ericas and rare alpine plants.

If you examine the two shots closely you see something odd.

At this distance, around 70 metres, the f7.1 aperture should be generating around 1 metre of DoF.

In the first shot the AF pont was pretty much on babys head, but the DoF run-out is a lot greater beyond that distance than it is closer to the camera.  If the shot had been taken wide open at f5.6 then the subject would not be as sharp as it is.  More of babys body should be sharp, and less foreground sharpness.

In the second shot I’ve wavered slightly right, so now the focus point is on mums ass. This SHOULD push the plain of focus further back – and thus that 1 metre DoF.  And it does – a bit! There is still too much foreground DoF.

The point is this, the focus tends to ‘bounce a little’ rather like the fault with the Nikon D4. This was caused, in the D4, by ‘mirror bounce’. But in the Canon 1DX Mk2 I get the feeling that it’s due to a nano-second miss timing between the AF sensor and the mirror starting to move for the next frame.

Why do I think this?  Because if I drop the frame rate from 10fps to 7fps the ‘AF bounce’ disappears completely.

I could put more images up to illustrate my point further but that would be pointless as it could be a fault unique to the camera I was using.  Having said that, there was another Canon 1DX Mk2 with a 200-400 shooting right next to me, and that showed exactly the same characteristics!!

But there is ONE thing I truly loathe on the Canon 1DX Mk2 – and the D5 and D500 come to that – the rear screen resolutions.

They are all too high in resolution.

I understand WHY they have such high resolutions, but when you are shooting stills at long distance, where focus placement is super-critical, they CAN lull you into something of a ‘false sense of security’ when you use them to check fine focus tolerances at 1:1.

You check the images on the camera and they look sharp.  You get back to base and offload the images to your storage drives then review them on a 13″ MacBook Pro with a damn 227 dpi Retina display and the still look sharp.  You get home and view them on your 90-odd dpi 24″ Eizo – and some of them look a lot less perfect!

I suppose with use it’s something you’ll get used to, but if you are moving to a Canon 1DX Mk2 from an older Mk1 or 5DMk3 then bare it in mind and check your images VERY carefully if you’re using big glass under critical conditions.

Anyway, back to the stunning Musk Ox again:

11I3397 Edit 600x400 Workshop Report and Canon 1DX Mk2 first thoughts

A solitary bull Musk Ox stands watch over his harem of females under the gloomy light of late afternoon in the Dovrefjell National Park in Norway.

11I2108 600x400 Workshop Report and Canon 1DX Mk2 first thoughts

Stormy skies form a backdrop to a bull Musk Ox standing watch over two females in his harem, ready to chase away any other bull that he may consider a threat to his dominance.

11I2101 600x400 Workshop Report and Canon 1DX Mk2 first thoughts

“Bam-Bam does Lunch”

Lack of Lemmings meant the Arctic Foxes were still up in the high ground, so with that and a very wet forecast for Sunday we elected to leave Dovrefjell a day early and do the 7 hour drive to Lauvsnes in order to gain an extra day with the Eagles.

Monday morning saw us in the boat at just after 6.30am and myself an “Mad” Mark Davies had one shot weighing heavily on our minds – Backlit Eagle!

Over the remaining days I have to say that we were spoilt something rotten with opportunities for this most enigmatic eagle shot, here is a tiny fraction:

11I4606 600x400 Workshop Report and Canon 1DX Mk2 first thoughts

11I5847 Edit 2 600x400 Workshop Report and Canon 1DX Mk2 first thoughts 11I5845 600x400 Workshop Report and Canon 1DX Mk2 first thoughtsThe Canon 1DX Mk2 performed perfectly on this job, no one could have asked it to do more.  Shooting this at 10 frames per second was epic as it captures more of the ‘money shots’ with the spray trails.

Here is a continuous burst of 77 raw files at 10 frames per second, from when the eagle begins its approach to when I can’t basically be bothered any more:

Screen Shot 2016 09 24 at 16.26.31 600x357 Workshop Report and Canon 1DX Mk2 first thoughts

And they are tack sharp from the first:

11I5833 600x400 Workshop Report and Canon 1DX Mk2 first thoughts

To the last:

11I5899 600x400 Workshop Report and Canon 1DX Mk2 first thoughts

 

I won’t say that by the end of the Thursday session it was getting boring, because I never cease to marvel at these awesome birds – but the hit-rate of the Canon 1DX Mk2 was getting a tad monotonous.

While a ‘crossing’ subject is not so taxing on the AF system as head-on subjects, the huge amounts of lens flare you encounter when shooting the style of image are notorious for playing havoc with auto focus.  When you get to the point of maximum rim lighting neither you or the camera can see very much of anything at all, and most older systems will hunt focus for a frame or two if you are not careful with your settings.

I shot sequences like this using both AF Point Surround and 9 point Zone AF – both of which performed superbly.

I’ll have to add a caveat though – the camera only performs this well if your technique is SOLID.  If you struggle to keep your AF group on target, or are just plain bone-idle, and try Large Zone AF or God forbid Auto, the cameras AF system goes into melt-down doing this sort of shot.

And yet AUTO on the Nikon D5 does a very good job at these sequences – weird!

So after a week of working the Canon 1DX Mk2 quite hard here’s what I think:

First, if you own a Mk1 1DX you NEED to upgrade, if only for the much superior IQ of the sensor.

Canon will probably hate me saying this, but the Canon 1DX Mk2 is ‘a bit of an animal’.  You could ‘wobble around’ a bit on the AF tracking with the Mk1 and get away with it.  But the Mk2 will bite you in the bum for doing the same thing – and when you least expect it.

With head-on targets the AF can both surprise and disappoint, methinks there will be a firmware upgrade at some point that will tidy the systems response to rapidly closing subjects at shortish distances.  That’s what happened with the Mk1.

11I7114 600x400 Workshop Report and Canon 1DX Mk2 first thoughts

There some other settings I need to play with on this beast of a machine before I feel I can formulate a descent opinion, things that I never had a chance to try in Norway, and others that only occur to me when viewing images on a PROPER SCREEN!

There is more to this ‘box of tricks’ from Canon than meets the eye!

And has anyone noticed just how CRAP the manual is – Jesus, I don’t think I’ve seen such a ‘sketchy’ document since I perused the Nikon D5 manual….sometimes I get the impression that both Nikon and Canon are a little clueless as to how there own gear works!

Makes me smile – and that’s a good thing!  But then again, it’s not my money being spent here – it’s yours.

A big thanks has to go to Paul Smith for supplying his camera and lens for this first evaluation – Cheers Matey!

And as always a big thank you to my clients, Mark, Malcolm, Mohamed & Paul for being such good sports, making a fun group dynamic, and for having a damn good laugh for week – usually at my expense!  Cheers for your continued support guys.

And lastly, Ole Martin – thanks again for yet another great week. Only another 9 months and I’m back for two weeks solid – Christ, won’t that be fun!!!

Nikon D5 Autofocus Test

Nikon D5 Autofocus Test

On Tuesday afternoon I had the opportunity to do a short Nikon D5 Autofocus test, courtesy of Paul Atkins.

D4D6793 900x599 Nikon D5 Autofocus Test

Using Paul’s newly acquired D5, his Nikon 400mm f2.8 lens and his two crackpot Golden retrievers ‘Enzo’ and ‘Raffa’, his large lawn and a couple of tennis balls, I gave the camera some hard work to do.

Bearing in mind that attentiveness, obedience and eagerness to please, are not traits that figure greatly in either dogs mental make-up; I was pleasantly surprised as to how instructive the exercise was – well done puppies!

On a good run at the camera the dogs cover something like 28 metres in 5 seconds, starting out at around 31 metres away and ending just outside the focus limiter at around 3 metres.

The camera was set to my MANUAL EXPOSURE + AUTO ISO, 1/4000th and f6.3.

I should also stress that there was NO AF FINE TUNE set for these shots.

That silliness has been taken to a whole new level of craziness now – sweet Jesus it makes me so angry!

I set the AF up very much how I’d set a Canon 1DX or 1DXMk2, and then went through the majority of the AF modes.

Dynamic 9, 25 and 72, group, 3D and ‘AUTO’ – and I was totally horrified at which mode gave the best results, and I mean BEST by a country mile!

In this video I go through the full resolution sequence of 27 shots individually so you can see how the Nikon D5 autofocus performs as the two dogs get closer to the camera with every frame.  The images have only Lightroom default sharpening applied and have had nothing done to them except my standard contrast-lowering adjustments.

Don’t be silly – click the YouTube link in the bottom of the above frame and watch it at full resolution on my channel!

Please don’t take this as a definitive test of the Nikon D5 autofocus – I certainly don’t, and neither am I prepared to draw much of a conclusion from it.  But it works!

I know I’m not alone in finding the Auto focus mode to be ‘better’ in terms of consistent focus, but to my mind this should NOT be the case, especially on such a target moving in such close proximity to a long telephoto – even if it is an f2.8.

At this point I’m not going to bother showing the sequences from the other modes, just take my word for it that I was shocked at the distinctly poorer performance using the other modes I tried – except for GROUP, which has never worked well in this sort of situation.

A couple of things to note:

  1. I used the same settings at 12fps and the consistency level dropped by around 45%, so no change in that old chestnut.  The Canon 1DX suffered from it too, but with the limited testing I’ve done on the 1DXMk2, Canons idea of crafting and honing the existing AF system, as opposed to Nikons ‘chucking the baby out with the bath water’, seems to have solved the problem to a greater degree.
  2. The D5 raw files seem to have lost a little tractability in ‘lifting the blacks/shadows/exposure’ – something that I’ve always held typical .NEF files in high esteem for.  This I found quite surprising seeing as the camera was heralded as the ‘Prince of Darkness’.   It’s also the one thing above all else that I despise in Canon 1DX raw files.  But Canon have upped their game considerably on this front with the 1DXMk2.

Seriously folks, it’s like some sort of demented see-saw or merry-go-round with these manufacturers…

The new Canon is coming to Norway with me in a couple of weeks, and Mr. Paul is bringing his D5, so there will be quite a bit of performance testing going on throughout September and October.

Hope these shots peek your interest folks!

 

Raw File Compression

Raw File Compression.

Today I’m going to give you my point of view over that most vexatious question – is LOSSLESS raw file compression TRULY lossless?

I’m going to upset one heck of a lot of people here, and my chances of Canon letting me have any new kit to test are going to disappear over the horizon at a great rate of knots, but I feel compelled to post!

What prompts me to commit this act of potential suicide?

It’s this shot from my recent trip to Norway:

FW1Q1351 2 900x600 Raw File Compression

Direct from Camera

FW1Q1351 900x600 Raw File Compression

Processed in Lightroom

I had originally intended to shoot Nikon on this trip using a hire 400mm f2.8, but right at the last minute there was a problem with the lens that couldn’t be sorted out in time, so Calumet supplied me with a 1DX and a 200-400 f4 to basically get me out of a sticky situation.

As you should all know by now, the only problems I have with Canon cameras are their  short Dynamic Range, and Canons steadfast refusal to allow for uncompressed raw recording.

The less experienced shooter/processor might look at the shot “ex camera” and be disappointed – it looks like crap, with far too much contrast, overly dark shadows and near-blown highlights.

Shot on Nikon the same image would look more in keeping with the processed version IF SHOT using the uncompressed raw option, which is something I always do without fail; and the extra 3/4 stop dynamic range of the D4 would make a world of difference too.

Would the AF have done as good a job – who knows!

The lighting in the shot is epic from a visual PoV, but bad from a camera exposure one. A wider dynamic range and zero raw compression on my Nikon D4 would allow me to have a little more ‘cavalier attitude’ to lighting scenarios like this – usually I’d shoot with +2/3Ev permanently dialled into the camera.  Overall the extra dynamic range would give me less contrast, and I’d have more highlight detail and less need to bump up the shadow areas in post.

In other words processing would be easier, faster and a lot less convoluted.

But I can’t stress enough just how much detrimental difference LOSSLESS raw file compression CAN SOMETIMES make to a shot.

Now there is a lot – and I mean A LOT – of opinionated garbage written all over the internet on various forums etc about lossless raw file compression, and it drives me nuts.  Some say it’s bad, most say it makes no difference – and both camps are WRONG!

Sometimes there is NO visual difference between UNCOMPRESSED and LOSSLESS, and sometimes there IS.  It all depends on the lighting and the nature of the scene/subject colours and how they interact with said lighting.

The main problem with the ‘it makes no difference’ camp is that they never substantiate their claims; and if they are Canon shooters they can’t – because they can’t produce an image with zero raw file compression to compare their standard lossless CR2 files to!

So I’ve come up with a way of illustrating visually the differences between various levels of raw file compression on Nikon using the D800E and Photoshop.

But before we ‘get to it’ let’s firstly refresh your understanding. A camera raw file is basically a gamma 1.0, or LINEAR gamma file:

LinVsHum3 900x271 Raw File Compression

Linear (top) vs Encoded Gamma

The right hand 50% of the linear gamma gradient represents the brightest whole stop of exposure – that’s one heck of a lot of potential for recording subtle highlight detail in a raw file.

It also represents the area of tonal range that is frequently most effected by any form of raw file compression.

Neither Nikon or Canon will reveal to the world the algorithm-based methods they use for lossless or lossy raw file compression, but it usually works by a process of ‘Bayer Binning’.

Bayer Pattern Raw File Compression

If we take a 2×2 block, it contains 2 green, 1 red and 1 blue photosite photon value – if we average the green value and then interpolate new values for red and blue output we will successfully compress the raw file.  But the data will be ‘faux’ data, not real data.

The other method we could use is to compress the tonal values in that brightest stop of recorded highlight tone – which is massive don’t forget – but this will result in a ’rounding up or down’ of certain bright tonal values thus potentially reducing some of the more subtle highlight details.

We could also use some variant of the same type of algorithm to ‘rationalise’ shadow detail as well – with pretty much the same result.

In the face of Nikon and Canons refusal to divulge their methodologies behind raw file compression, especially lossless, we can only guess what is actually happening.

I read somewhere that with lossless raw file compression the compression algorithms leave a trace instruction about what they have done and where they’ve done it in order that a raw handler programme such as Lightroom can actually ‘undo’ the compression effects – that sounds like a recipe for disaster if you ask me!

Personally I neither know nor do I care – I know that lossless raw file compression CAN be detrimental to images shot under certain conditions, and here’s the proof – of a fashion:

Let’s look at the following files:

14bitUC1 258x400 Raw File Compression

Image 1: 14 bit UNCOMPRESSED

14bitUC2 258x400 Raw File Compression

Image 2: 14 bit UNCOMPRESSED

14bitLosslessC 258x400 Raw File Compression

Image 3: 14 bit LOSSLESS compression

14bitLossyC 258x400 Raw File Compression

Image 4: 14 bit LOSSY compression

12bitUC 258x400 Raw File Compression

Image 5: 12 bit UNCOMPRESSED

Yes, there are 2 files which are identical, that is 14 bit uncompressed – and there’s a reason for that which will become apparent in a minute.

First, some basic Photoshop ‘stuff’.  If I open TWO images in Photoshop as separate layers in the same document, and change the blend mode of the top layer to DIFFERENCE I can then see the differences between the two ‘images’.  It’s not a perfect way of proving my point because of the phenomenon of photon flux.

Photon Flux Andy??? WTF is that?

Well, here’s where shooting two identical 14 bit uncompressed files comes in – they themselves are NOT identical!:

controlunamplified 258x400 Raw File Compression control 258x400 Raw File Compression

The result of overlaying the two identical uncompressed raw files (above left) – it looks almost black all over indicating that the two shots are indeed pretty much the same in every pixel.  But if I amplify the image with a levels layer (above right) you can see the differences more clearly.

So there you have it – Photon Flux! The difference between two 14 bit UNCOMPRESSED raw files shot at the same time, same ISO, shutter speed AND with a FULLY MANUAL APERTURE.  The only difference between the two shots is the ratio and number of photons striking the subject and being reflected into the lens.

The Levels Adjustment Layer had values of 0, 50 and 150, and is going to be added to the following comparison images:

Firstly 14 Bit UNCOMPRESSED compared to 14 bit LOSSLESS (the important one!):

14bitUCvLosslessC 258x400 Raw File Compression

14 bit UNCOMPRESSED vs 14 bit LOSSLESS

Please remember, the above ‘difference’ image contains photon flux variations too, but if you look carefully you will see greater differences than in the ‘flux only’ image above.

14bitUCvLossyC 258x400 Raw File Compression 14bitUCv12bitUC 258x400 Raw File Compression

The two images above illustrate the differences between 14 bit uncompressed and 14 bit LOSSY compression (left) and 14 bit UNCOMPRESSED and 12 bit UNCOMPRESSED (right) just for good measure!

In Conclusion

As I indicated earlier in the post, this is not a definitive testing method, sequential shots will always contain a photon flux variation that ‘pollutes’ the ‘difference’ image.

I purposefully chose this white subject with textured aluminium fittings and a blackish LED screen because the majority of sensor response will lie in that brightest gamma 1.0 stop.

The exposure was a constant +1EV, 1/30th @ f 18 and 100 ISO – nearly maximum dynamic range for the D800E, and f18 was set manually to avoid any aperture flicker caused by auto stop down.

You can see from all the ‘difference’ images that the part of the subject that seems to suffer the most is the aluminium part, not the white areas.  The aluminium has a stippled texture causing a myriad of small specular highlights – brighter than the white parts of the subject.

What would 14 bit uncompressed minus 14 bit lossless minus photon flux look like?  In a perfect world I’d be able to show you accurately, but we don’t live in one of those so I can’t!

We can try it using the flux shot from earlier:

losslessminuscontrol 258x400 Raw File Compression

But this is wildly inaccurate as the flux component is not pertinent to the photons at the actual time the lossless compression shot was taken.  But the fact that you CAN see an image does HINT that there is a real difference between UNCOMPRESSED and LOSSLESS compression – in certain circumstances at least.

If you have never used a camera that offers the zero raw file compression option then basically what you’ve never had you never miss.  But as a Nikon shooter I shoot uncompressed all the time – 90% of the time I don’t need to, but it just saves me having to remember something when I do need the option.

FW1Q4469 600x400 Raw File Compression

Would this 1DX shot be served any better through UNCOMPRESSED raw recording?  Most likely NO – why?  Low Dynamic Range caused in the main by flat low contrast lighting means no deep dark shadows and nothing approaching a highlight.

I don’t see it as a costly option in terms of buffer capacity or on-board storage, and when it comes to processing I would much rather have a surfeit of sensor data rather than a lack of it – no matter how small that deficit might be.

Lossless raw file compression has NO positive effect on your images, and it’s sole purpose in life is to allow you to fit more shots on the storage media – that’s it pure and simple.  If you have the option to shoot uncompressed then do so, and buy a bigger card!

What pisses my off about Canon is that it would only take, I’m sure, a firmware upgrade to give the 1DX et al the ability to record with zero raw file compression – and, whether needed or not, it would stop miserable grumpy gits like me banging on about it!

 

Night Sky Imaging

Night Sky Photography – A Brief Introduction

D8E3685 3690composite23 Night Sky Imaging

I really get a massive buzz from photographing the night sky – PROPERLY.

By properly I mean using your equipment to the best of its ability, and using correct techniques in terms of both ‘shooting’ and post processing.

The majority of images within the vast plethora of night sky images on Google etc, and methods described, are to be frank PANTS!

Those 800 pixel long-edge jpegs hide a multitude of shooting and processing sins – such as HUGE amounts of sensor noise and the biggest sin of all – elongated stars.

Top quality full resolution imagery of the night sky demands pin-prick stars, not trails that look like blown out sausages – unless of course, you are wanting them for visual effect.

Pin sharp stars require extremely precise MANUAL FOCUS in conjunction with a shutter speed that is short enough to arrest the perceived movement of the night sky across the cameras field of view.

They also demand that the lens is ‘shot’ pretty much wide open in terms of aperture – this allows the sensor to ‘see and gather’ as many photons of light from each point-source (star) in the night sky.

So we are in the situation where we have to use manual focus and exposure with f2.8 as an approximate working aperture – and high ISO values, because of the demand for a relatively fast shutter speed.

And when it comes to our shutter speed the much-vaunted ‘500 Rule’ needs to be consigned to the waste bin – it’s just not a good enough standard to work to, especially considering modern high megapixel count sensors such as Nikon’s D800E/D810/D810A and Canons 5DS.

Leaving the shutter open for just 10 seconds using a 14mm lens will elongate stars EVER SO SLIGHTLY – so the ‘500 Rule’ speed of 500/14 = 35.71 seconds is just going to make a total hash of things.

In the shot below; a crop from the image top left; I’ve used a 10 second exposure, but in preference I’ll use 5 seconds if I can get away with it:

D8E3690 Night Sky Imaging

Nikon D800E,14-24 f2.8@14mm,10 seconds exposure,f2.8,ISO 6400
RAW, Unprocessed, Full Resolution Crop

WOW….look at all that noise…well, it’s not going to be there for long folks; and NO, I won’t make it vanish with any Noise Reduction functions or plugins either!

1444x1444testcomposite Night Sky Imaging

5 consecutive frames put through Starry Landscape Stacker – now we have something we can work with!

Download Starry Landscape Stacker from the App Store:
%name Night Sky Imaging

Huge amounts of ‘noise’ can be eradicated using Median Stacking within Photoshop, but Mac users can circumnavigate the ‘agro’ of layer alignment and layer masking by using this great ‘app’ Starry Landscape Stacker – which does all the ‘heavy lifting’ for you.  Click the link above to download it from the App Store.  Just ignore any daft iTunes pop-ups and click ‘View in Mac App Store’!

I have a demonstration of Median Stacking on my YouTube channel:

This video is best viewed on YouTube in full screen mode.

In a manner of speaking, the ‘shooting aspect’ of Milky Way/Night Sky/Wide-field Astro is pretty straight forward.  You are working in between some very hard constraints with little margin for error.

  • The Earths rotation makes the stars track across our frame – so this dictates our shutter speed for any given focal length of lens – shorter focal length = longer shutter speed.
  • Sensor Megapixel count – more megs = shorter shutter speed.
  • We NEED to shoot with a ‘wide open’ aperture, so our ISO speed takes over as our general exposure control.
  • Focusing – this always seems to be the big ‘sticking point’ for most folk – and despite what you read to the contrary, you can’t reliably use the ‘hyperfocal’ method with wide open apertures – it especially will not work with wide-angle zoom lenses!
  • The Earths ‘seasonal tilt’ dictates what we can and can’t see from a particular latitude; and in conjunction with time of day, dictates the direction and orientation of a particular astral object such as the Milky Way.
  • Light pollution can mask even the cameras ability to record all the stars, and it effects the overall scene luminance level.
  • The position and phase of the moon – a full moon frequently throws far too much light into the entire sky – my advice is to stay at home!
  • A moon in between its last quarter and new moon is frequently diagonally opposite the Milky Way, and can be useful for illuminating your foreground.

And there are quite a few other considerations to take into account, like dew point and relative humidity – and of course, the bloody clouds!

The point I’m trying to make is that these shots take PLANNING.

Using applications and utilities like Stellarium and Photographers Ephemeris in conjunction with Google Earth has always been a great way of planning shots.  But for me, the best planning aid is Photopills – especially because of its augmented reality feature.  This allows you to pre-visualise your shot from your current location, and it will compute the dates and times that the shot is ‘on’.

Download Photopills from the App Store:

Photopills400x400bb 150x150 Night Sky Imaging

But it won’t stop the clouds from rolling in!

Even with the very best planning the weather conditions can ruin the whole thing!

I’m hoping that before the end of the year I’ll have a full training video finished about shooting perfect ‘wide field astro’ images – it’ll cover planning as well as BOTH shooting AND processing.

I will show you how to:

  • Effectively use Google Earth in conjunction with Stellarium and Photopills for forward planning.
  • The easiest way to ensure perfect focus on those stars – every time.
  • How to shoot for improved foreground.
  • When, and when NOT to deploy LONG EXPOSURE noise reduction in camera – black frame shooting.
  • How to process RAW files in Lightroom for correct colour balance.
  • How to properly use both Median Stacking in Photoshop and Starry Landscape Stacker to reduce ISO noise.
  • And much more!

One really useful FREE facility on the net is the Light Pollution Map website – I suggest using the latest 2015 VIIRIS overlay and the Bing Map Hybrid mode in order to get a rough idea of your foreground and the background light pollution effecting your chosen location.

Don’t forget – if you shoot vertical (portrait?) with a 14mm lens, the top part of the frame can be slightly behind you!

 

 

Autofocus Guide for Long Lens Bird in Flight Photography

GX2R2055 Edit 21 Autofocus Guide for Long Lens Bird in Flight Photography

My Autofocus Guide for Bird in Flight Photography is finished and available for download in my online store – here, priced £29.00

The download is in the no-frills .pdf format.

Screen Shot 2016 12 10 at 12.20.12 352x400 Autofocus Guide for Long Lens Bird in Flight Photography

This is my ‘real world’ guide to Canon & Nikon Autofocus which is specifically aimed at photographers using long lenses for Bird in Flight photography.

I sell my full resolution wildlife and natural history images every day via the various global image libraries to which I am a contributor.  The largest percentage of these sales are Birds in Flight.

Image libraries demand tack sharp, full resolution uploads from their contributors;  even marginal sharpness will result in an image being rejected by Quality Control.

D4D7980 Edit Autofocus Guide for Long Lens Bird in Flight Photography

A large male White-tailed eagle, locally known as “Brutus”, carrying a very large Coalfish.

In this guide, I take you right back to the basics of subject speed and distance; and how this impacts on our choice of camera body and lens focal length and working aperture.

D4S6788 Edit Edit Autofocus Guide for Long Lens Bird in Flight Photography

A Red Kite in a fast dive against a blue sky.

You’ll learn how phase detection autofocus works – only by really understanding how your autofocus system works, and what its control settings actually do, will you truly be able to control it in the way you need to for the particular task at hand.

I give you exposure and autofocus control settings for both Canon and Nikon, based on ‘real world’ full resolution images – settings that actually work, and do the job you expect them to do.

We also discover the various ‘tips ‘n tricks’ we need to know to help the autofocus system do the job we are asking it to do.

We also look at the short-comings of both the Nikon and Canon systems, and how to work around them in order to produce tack sharp images of birds in flight – HAND HELD – forget that tripod; you can’t move fast enough with one!

Photographers who have read this guide as it was being written have called it ‘the definitive guide’.  I’m not going to be so big-headed as to promote it as such myself, but I will say that it’s taken a while to produce, is pretty darn thorough, and I have the shots to prove it!

Available for purchase in my online store right now.

Please Note: This document relates to LONG LENS continuous auto focus tracking in Nikon AFC and Canon AI Servo modes in conjunction with continuous shooting modes on Nikon D4/4S and Canon 1Dxbodies with v2 firmware or higher, and is primarily related to capturing Birds in Flight and other fast-paced wildlife action photography.
Canon 5DMk3/7DMk2 users will also find this guide very useful, as will non-wildlife shooters.

Lee SW150 Mk2 Filter Holder – Review

The Lee SW150 Mk2 Filter Holder

D4D3598 Edit Lee SW150 Mk2 Filter Holder   Review

PURE SEX – and I’ve bloody well paid for this! My new SW150 MkII filter system for the Nikon 14-24. Just look at those flashy red anodised parts – bound to make me a better photographer!

I’ve just finished part 1 of my video review of the Lee SW150 Filter holder system for super-wide lenses and uploaded it to my YouTube channel:

First off – please forgive the shirt folks!

The SW150 Mk 2 filter holder is designed to fit a list of different lenses:

  1. Nikon AF-S Nikkor 14-24mm f/2.8G ED

  2. Nikon 14mm f2.8 D AF ED

  3. Canon EF 14mm f2.8 L II USM

  4. Samyang 14mm f/2.8 ED AS IF UMC

  5. Sigma 12-24mm f4.5-5.6 DG HSM II

  6. Tokina AT-X 16-28mm f/2.8 PRO FX

and according to the Lee website, additional lenses will be catered for; as the need arises I presume.

I never subscribed to the original incarnation of the SW150, for two reasons:

  • It ‘leaked light’ at the rear surface of the filter (though that was fairly easy to correct with a home-made baffle mod).

But that was of no consequence to me because Lee always gave the impression that:

  • They would not produce the Big & Little Stopper filters in 150mm square format.

So I’ve always stuck with either the 100mm Lee system or used a B&W 77mm screw-in filter on the Nikon 24-70mm f2.8 or a wide angle prime; and I’ve shot many a well-selling image.

nik14 24 24 70 Lee SW150 Mk2 Filter Holder   Review

But, the Nikon 14-24mm f2.8 lens has more than one advantage over its sister lens:

  1. It’s sharper – by a country mile.
  2. It resolves more ‘line pairs per millimetre’ than the 24-70mm.
  3. Its focal length range is more ‘in keeping’ with landscape photography.

And, like all the other lenses in that list above, that vast front element collects SO MANY MORE photons during the exposure.

So, now that I’ve got the opportunity to use the advantages of the 14-24 f2.8 from behind high quality 10x and 6x ND filters – well, let’s say the purchase of the Lee SW150 Mk2 system is a bit of a ‘no-brainer’ really.

The main improvement to the holder itself is the inclusion of a new baffle or ‘lightshield’ as Lee call it – this can be purchased separately as an upgrade to the original Lee SW150 Mk 1.

But you’ll have to do without the sexy red anodised bits that come with the new Mk 2 version if you go that route – these have just got to make me a better photographer!

I’ll be doing part 2 of this video review in the near future, as and when time and weather permit; but for now, I hope you find this video useful folks.

Please consider supporting this blog.

This blog really does need your support. All the information I put on these pages I do freely, but it does involve costs in both time and money.

If you find this post useful and informative please could you help by making a small donation – it would really help me out a lot – whatever you can afford would be gratefully received.

Your donation will help offset the costs of running this blog and so help me to bring you lots more useful and informative content.

Many thanks in advance.

 

Image Retouching

 Image Retouching in Photoshop CC 2014

It’s very rare that we ever get a frame from our camera that doesn’t need retouching – that’s a FACT.

Imperfections in the frame can be both ‘behind the shutter’ and ‘in front of the lens’ – sensor dust and crud on the subject.  But you’ll take photographs where these imperfections are hard, if not impossible, to see under normal viewing.

But print that image BIG and those invisible faults will begin to be visually apparent; by which time it’s too bloomin’ late and they’ve cost you money; or worse still, a client.

The ‘visualise spots’ tool in Lightroom will show you a certain amount of ‘dust bunny’ type faults and errors, but the way Lightroom executes retouching repairs is not always ‘quite up to snuff’; and when it comes to dust, crap and other undesirables on the subject itself Lightroom will fail to recognise them in the first place.

Image retouching isn’t really all that difficult; but it can be an intensely tedious and time-consuming process.

To that end I’ve stuck these HD video lessons on my You Tube channel.

In these videos I illustrate how I deploy the Spot Healing brush, Healing Brush, Clone Tool, Patch Tool and Content Aware Fill command to carry out some basic image retouching on a shot of cutlery bright ware.

I demonstrate the addition of a ‘dust visibility’ curves adjustment layer – something that everyone should ‘get the hang’ of using – as a first step to effective image retouching.

When photographing glossy, high reflectivity subjects we need to remove the imperfections and smooth the surfaces of the subject without reducing the ‘glossiness’ and turning it matt!

Please note: a couple of these videos are in excess of 20 minutes duration and they will look better at full resolution HDV if you click the You Tube icon. Also, it takes a lot longer to do a job when you have to talk about at the same time!

I hope you get some idea as to how simple and straightforward my approach to image retouching is!

Please consider supporting this blog.

This blog really does need your support. All the information I put on these pages I do freely, but it does involve costs in both time and money.

If you find this post useful and informative please could you help by making a small donation – it would really help me out a lot – whatever you can afford would be gratefully received.

Donations would help offset the costs of running this blog and so help me to bring you lots more useful and informative content.

Many thanks in advance.