Irix 15mm Blackstone f2.4 – First Night Test

 Irix 15mm Blackstone f2.4 – First Night Test

As I said way back in my in-depth review of this awesome bit of kit, I was originally interested in the Astro photography potential of the Irix 15mm Blackstone/Firefly lens.

Monday night – 24th July – saw myself and Rik heading for Snowdonia in North Wales, and in particular the small wooden foot bridge over Afon Idwal, just a ways up the old miners track behind Ogwen Cottage.

The weather forecast was for clear skies, and Google Earth in conjunction with Stellarium and TPE told me that around 11 pm the Milky Way would be over said small wooden bridge.  So we packed a few things and off we toddled.

Irix 15mm Blackstone f2.4 - First Night Test

IMPORTANT: THERE IS NO SHARPENING ON THIS IMAGE. All 33 image frames (32 light frames plus the long exposure frame) had ZERO sharpening applied during processing. The Milky Way towers high in the night sky over the mountains of Snowdonia in North Wales. A small wooden footbridge over the rushing waters of the River Idwal forms the focal point.

The place was rammed with people coming down off the mountains – and a pile going up as well – as it transpires, they were having an all-night party on the shores of Llyn Idwal higher up the track – nutters!

The Welsh midges were out in force and doing their best impression of man-eating tigers and guess who forgot to bring the mozy repellent!

The composition I was after entailed me setting up on the path and shooting straight along the bridge,  so I set the camera up with the Irix 15mm Blackstone set on the infinity click stop and the focus locked with the locking ring.  I knew from all the testing I’d done that this would give my tack sharp stars even with the aperture wide open and that stopping down to f6.3 or narrower would render a sharp foreground to around 1.5 metres.

The ‘plan’ was to shoot a foreground image at low ISO during twilight in order to save having to shoot a long exposure with LENR under total darkness – and that’s exactly what I did, then it all went a bit ‘Pete Tong’!

What caused the confusion was my Photpills app on my iPhone telling me that the Milky Way was already where I needed it to be in about another hour and a half, so the whole shot was not going to work – bear in mind the sky is still too bright to see any stars.

So like an idiot I believed it and moved the camera, looking for another composition that would work – as it transpired a fatal mistake.

A lesson for the future – if a mobile app does not match up with Stellarium, the Photographers Ephemeris and Google Earth try restarting the phone and re-calibrating the compass!!

After 45 minutes of struggling to find another composition using the new projected position of the Milky Way in the growing darkness, I looked up and saw the Summer Triangle – in exactly the position that my original plan had calculated.

After a short bout of self-directed expletives based around men’s dangly-bits and the act of procreation, I got the camera back in something approximating its original position, but of course, the original framing would be ‘off’ so my initial low ISO foreground shot was useless.

Starting over, I set the camera to shoot 32 frames in continuous low and used a locking cable release to shoot  rapid sequences of 32 frames – an easy way to do the job that does not always work too well with a big zoom like the Nikon 14-24, or Canon 16-35 – occasionally you can get ‘mirror vibration’ effects on your images.  But with a short-barreled prime like the Irix 15mm, this is not a problem I ever see.

By around 11.30pm I’m happy with the sky shots I have in the can, but now comes the long exposure foreground shot.

I’m actually dreading this shot as it’s going to take a long time to produce and I’m anticipating some of those aforementioned party goers to come wandering back down the track with head-torches waving around all over the place.

I opted for a 10-minute exposure with long exposure noise reduction enabled in the camera – so the shot is going to take 20 minutes to produce.

Twenty minutes later, the shot on the back of the camera indicated that in reality, it needed around another stop and a half-ish of exposure time.  I’d got away with no torches wandering through this shot, but if I did another, longer one I was certain it would get ruined.

So I shot 32 dark frames and another couple of 32 frame sequences, then we packed the gear away and headed for home.

Irix 15mm Blackstone f2.4 - First Night Test

The total number of frames for this shot with the Irix 15mm was 85 and comprise of:

  • 32 light frames 6secs @f4 6400 ISO
  • 32 dark frames 6secs @f4 6400 ISO
  • 1x 600sec @f6.3 400 ISO – (no need for re-focus so no focus breathing problems).
  • 20 frames to make the master flat file

(If you to learn why we shoot so many frames and what to do with them all then buy my latest Astro photography training video HERE).

Irix 15mm

Made from 32 images with 32 dark frames and a flat-field frame by Starry Landscape Stacker 1.4.0. Click to view full size.

As you can see from the image above, stars are tack sharp (even with no sharpening added in post), and coma is minimal.  And most importantly there is plenty of colour in those fainter stars – something that is a little harder to achieve with the ubiquitous Zeiss glass.

I could improve the image quality even further by correct that minimal coma in Photoshop with a custom brush and the clone tool, and make a star mask and reduce the noise even more (see my training videos if you want to know more!).

And of course, if I hadn’t had the wobble over composition then perhaps I would have ended up with something like this:

Irix 15mm

Or something in between the two!

But either way, the session proved to equal or exceed my expectations of this Irix 15mm lens capabilities.

So, am I impressed by how this lens performs under Astro photography conditions?  You bet I am!

I’ll never use my trusty Nikon 14-24 for Astro photography ever again as far as I can see – why would I…

Sharp focus with the Irix 15mm is so easy to achieve, and there is now no reason to re-focus on closer foreground objects – all I need to do is stop down the aperture a bit.  So that’s all those focus-breathing errors out the window for starters.

Then, there is less coma, less chromatic aberration and a lot less barrel distortion.

When fumbling around in the dark, personally I think it would be good if Irix could increase the diameter of the focus locking ring, but that’s such a minor point it’s only just barely worth a mention.

What’s next?

Irix have just sent me a set of their new Edge 95mm screw-in filters, including 10x and 7x ND filters and the circular polarizer – so some daytime landscapes seem to be in order over the next couple of weeks.

I just wish I’d had the 11mm for the shot of the Milky Way!

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Twilight & Astro Landscape Photography

Twilight & Astro Landscape Photography

Everyone likes a nice moody sunset, but great images await those camera operators that start shooting after most folks have started packing their gear away and heading home.

For me, twilight is where the fun starts.

Twilight & Astro Landscape Photography

The rock stack lying off the boulder-strewn beach of Porth Saint, Rhoscolyn Head, Anglesey.

The low light levels on a scene once ‘civil daylight’ has ended mean you get awesome light with lower contrast shadows, subtle skies, and nice long shutter speeds for dreamy water effects without needing expensive 10 stop ND filters.

However, that awesome light vanishes very quickly, so you have to be ready!  I waited nearly 90 minutes for the shot above.

But that time was spent doing ‘dry runs’ and rehearsals – once the composition was set how I wanted it, the foreground was outside of DoF, so I knew I needed to shoot a focus stack as well as an exposure blend…mmmm….yummy!

Once we have made the long transition from civil daylight end to astronomical daylight end the fun really begins though.

Astro Landscape Photography

Twilight & Astro Landscape Photography

The Milky Way over the derelict buildings of Magpie Mine in Derbyshire.

Astro landscape photography, or wide field astro as it’s sometimes known, is not as difficult as a lot of photographers imagine.

But astro landscape photography IS very demanding of your familiarity with your gear, and will require some expenditure on additional bits of kit if disappointment is to be avoided.

Twilight & Astro Landscape Photography

 

Twilight & Astro Landscape PhotographyTwilight & Astro Landscape PhotographyHere’s the kit I usually venture out at night with:

Dew Heater Band (A).

An essential bit of kit for astro landscape photography – it’s amazing how rapidly a lot of lenses, especially super-wides like the Nikon 14-24 f2.8 encounter a problem with dew at night.  This will in effect fog the front element, starting at its centre and if left unchecked it can spread across the entire face of the lens.

Heating the lens front sufficiently to keep its temperature above the dew point for your current location and time will prevent a ruined session – don’t leave home without one!

This dew heater is powered by a battery (C) via a dew heater controller (D) with is basically a simple rotary rheostat which controls the level of current driving the heater band.

I use mine at about 75% of ‘full chat’ and it seems to work just fine.

A final note on dew heater bands – these are designed for use by those strange folk who spend hours behind telescopes.  They tape the bands in place and leave them there.  As photographers we need to add or remove them as needed.  The bands can prove fragile, need I say more?

Yes, it pays to carry a spare, and it pays to treat them with care and not just throw them in the camera bag – I’m on band number 3 with number 4 in reserve!

Intervalometer (B).

You will need to shoot a long exposure of you scene foreground, slightly re-focuused closer to you, at a much lower ISO, and perhaps at a slightly narrower aperture; this shot might well be 20 minutes long or more and with long exposure NR engaged to produce a black subtraction.

Yes, a lockable cable release and the timer on your watch will do the job, hence (F) and (G) in case (B) stops working!

But an intervalometer will make this easier – as long as you’ve read the instructions..doh!

If you want to shoot star trails the external intervalometer is vastly superior to your cameras built in one.  That’s because the in-camera intervalometer on nearly all cameras except the Nikon D810A is limited to a 30 second shutter speed.

An hours worth of star rotation is barely enough:

Twilight & Astro Landscape Photography

 

But at 30 seconds shutter speed you will end up with 120 frames at fairly high ISO.

Far better to shoot at ‘bulb’ with a 5 minute exposure and lower ISO – then you’ll only have 12 frames – your computer with thank you for the lower number when it comes to stacking the shots in Photoshop.

There is also another problem, for certain marks of Nikon cameras.  The D800E that I use has a stupid cap on continuous shooting.  The much touted method of setting the shutter to 30 seconds and putting the camera in continuous low speed shooting mode and locking the cable release button down does NOT work – it only allows you to take 100 frames then the camera just STOPS taking pictures.

But if you use an external intervalometer set to a 30 second exposure, continuous and just drop the camera in BULB and Single Shot then the D800E and its like will sit there and fill your cards up with frames.

Other Essentials.

Micro fibre cloths, bin liners and gaffer tape (B,I and J).

After a couple of hours of full darkness your gear (and I mean all of it) will most likely be wet with dew, especially here in the UK.  Micro fibre cloths are great for getting the majority of this dampness off your camera gear when you put it away for the trip home.

Bin liners are great for keeping any passing rain shower off your camera gear when its set up – just drop one (opened of course) over your camera and tape it to the tripod legs with a bit of gaffer tape. Leave the dew heater ON.

Also, stick the battery supply in one – rain water and 13 volts DC at 4000MAh don’t mix well.

Photopills on your iPhone (G) is incredibly useful for showing you where the Milky Way is during that extended period between civil and astronomical daylight end.  Being able to see it in relationship to your scene with the Night Augmented Reality feature cetainly makes shot composition somewhat easier.

Head Lamp (H) – preferably one which has a red light mode.  Red light does not kill off your carefully tuned night vision when you need to see some camera setting control lever or button.

Accurate GPS positioner (K).  Not entirely an ‘essential’ but it’s mighty useful for all sorts of reasons, especially when forward planning a shot, or getting to a set position in the dark.

Twilight & Astro Landscape Photography

The Milky Way towering over the National Coastwatch Institution (NCI) station at Rhoscolyn on Anglesey.

 

I love taking someone who’s never seen the Milky Way out at night to capture it with their own equipment – the constant stream of ‘WOWS’ makes me all warm ‘n fuzzy!  This year has seen me take more folk out than ever; and even though we are going to loose the galactic centre in the next few weeks the opportunities for night photography get better as the nights grow longer.

Twilight & Astro Landscape Photography

The Milky Way over the derelict buildings of Magpie Mine in Derbyshire.

So if you want to get out there with me then just give me shout at tution@wildlifeinpixels.net

The Milky Way will still be a prominent feature in the sky until October, and will be in a more westerly position, so lots of great bays on the North Wales & Anglesey coast will come into their own as locations.

Astro Landscape Photography

The Milky Way over the Afon Glaslyn Valley looking towards Beddgelert and Porthmadog. The patchy green colour of the sky is cause by a large amount of airglow, another natural phenomenon that very few people actually see.

And just look at that star detail:

Astro Landscape Photography

Over the next few weeks I’m going to be putting together a training video title on processing astro landscape photography images, and if the next new moon phase at the end of this month comes with favorable weather I’m going to try and supplement these with a couple of practical shooting videos – so fingers crossed.

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Night Sky Imaging

Night Sky Photography – A Brief Introduction

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:

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

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!

6 consecutive frames put through Starry Landscape Stacker

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

Download Starry Landscape Stacker from the App Store:
icon175x175

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

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!

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