Lens Review – Irix Blackstone 15mm f2.4

Posted on May 29, 2017 by Andrew Astbury

Irix Blackstone 15mm f2.4

Irix Blackstone 15mm f2.4

I heard a few rumors about the new Irix lenses before I went to Iceland back in March, but could I find one to even look at let alone test – no, they seemed as elusive as hens teeth.

But last month I was invited by the Irix marketing and distribution team to give one a beating!

The one lens in the range that piqued my interest the most was the Irix Blackstone 15mm f2.4 – and here’s why:

F2.4
Supposed lack of CA
Supposed lack of barreling
15mm PRIME
Focus locking ring
Hard focus stops
Infinity click/detent
Good old-fashioned engraved focus scale with DoF, IR and hyperfocal markings
Solid all-metal construction
Removable lens hood – the importance of this will be pointed out later.
Price point – for the money this lens COULD represent epic value for money – but only testing & evaluation will confirm that.

All-in-all the lens appeared to be a dream for wide-field astro photography and sweeping vista landscapes – just such a shame I couldn’t get hold of one for my Iceland trip.

So a couple of weeks ago I met up with Charles Woods of Charles Talks fame – a real nice guy who moves in far higher circles than I do being the go-to contact for Leaf, Cambo and many other gorgeous lines of photographic loveliness. If Charles takes on a brand then it’s worthy of some very serious considerations.

The Lens:

The Irix Blackstone 15mm f2.4 packaging is like a babushka – it’s a lens in a semi-rigid case, in a tin, in a box! (excuse the slightly dog-eared box but it’s been around a bit!).

Inside the tin you will also find a world-wide warranty card, a multi-lingual introduction booklet – AND, a SPARE rear lens cap; a nice touch Irix.

Irix Blackstone 15mm f2.4

Open the zipped case and there is your lens with the lens hood reversed:

Irix Blackstone 15mm f2.4

Remove the lens, turn the lens hood around, line up the registration lines on the hood and lens, then twist until it locks into position:

Irix Blackstone 15mm f2.4

A couple of interesting features on the lens you MAY find useful:

Irix Blackstone 15mm f2.4

On the underside of the lens hood (if it’s on the top you’ve got the hood upside down) you will see a sliding door. If you push this forward it will reveal a gap – fit a 95mm screw-in polarizer and you can rotate it as necessary then slide the door back until it ‘clicks’ shut.

And on the rear of the lens there is a built-in gelatin filter holder – Irix have put a lot of thought into the ‘bells & whistles’ on these lenses.

My Thoughts – personally I have to say that these two features may well be very useful for studio/indoor photography BUT – try fitting tiny gelatins in a force eight gale when shooting landscapes! And as for polarizing filters – they never really work well on lenses with such a wide angle of view because their effects are virtually non-existent on all but the center of the image.

It’s vitally important that the filter access door is ‘clicked’ closed, otherwise it can cause a small amount of flaring – I’ve taped it on the outside so I can’t open it by accident, and I’ll be using 150×150 filters and a 95mm adapter ring for the holder.

Being a bit ‘old skool’ I’m never a big fan of light weight plastic lenses if truth be told,especially when it comes to wide angles. So holding the Irix Blackstone 15mm f2.4 is a real pleasure for me with its all metal construction, and honestly, it’s built like a tank.

The lens itself is manual focus only and available in Nikon F, Pentax K & Canon EF mount options, and features a 9 curved-blade aperture together with 15 elements in 11 groups.

Irix Blackstone 15mm f2.4

The focus ring is silky smooth and has more resistance than your typical Zeiss Distagon, which in my opinion is a good thing. The other attribute of the focus ring is the long throw, which is a lot longer than the 15mm Distagon and comparing it to the short throw, fast focus ring on the venerable Nikon 14-24, this Irix lens should be a dream to use for both daytime and night landscape photography.

I have to add a note here about the focus ring on the Nikon 14-24. It is far too fast/short for precise manual focus without a heck of a lot of practice.

Focus Scale & Focus Locking Ring:

Irix Blackstone 15mm f2.4

Just ahead of the main focus ring is the focus locking ring – one of the main features of the lens I found piquing my interest in the first place, especially for wide-field astro work where focus is super critical, and accidental movement of the focus ring easily happens. In the image above the focus is not quite fully unlocked – the unlock indicator should be just about in line with main focus indicator line on the focus scale/vertical white line after the ’15’ on the lens bell for normal focus operation. Turn the locking ring to the left until it stops – don’t over tighten/force it – and your focus is locked.

The focus scale itself is excellent, and packed with all the information you could ever need if truth be told.

There is a definite ‘click’ as you focus at infinity, and there is even an infra-red focus mark. You have DoF indicators for f8, 11 & 16 together with hyperfocal distance markings for the same apertures.

There is also one more feature of this lens that I have not mentioned yet, and that’s because it isn’t something you should really ‘mess about’ with unless you know what you are doing! I am talking about this on the underside of the lens bell:

Irix Blackstone 15mm f2.4

Details of how to use this feature can be found on Page 8 of the downloadable Extended User manual HERE.

My Thoughts – just about every manufacturer of lenses of this focal length will do a ‘factory infinity calibration’ calculated at beyond 50 meters.

As a landscape photographer your eye level horizon at sea level is around 4700m, and the clouds touching the horizon may be well over 100km away. Focused at infinity and stopped down to f11 or f16 they WILL be sharp due to DoF.

However, shooting the sky at night at f2.4, f2.8 – in other words with NO DoF to help you out – you will invariably find that you need to focus just before, or more rarely just after, the infinity mark in order to get those stars tack sharp.

A close star like Arctaurus is more than 36.5 light years away, and Polaris – the Pole Star here in the northern hemisphere – is 433.8 light years away. What I’m trying to say here is that there are many ‘degrees of infinity’ and some types of photography require greater accuracy than others.

Experience has taught me that at 14mm and f2.8 sharp focus on street lights at night from around 15km and an elevated position work perfectly for pin-sharp stars. Some people then tape the lens focus ring, but using the focus locking ring on the Irix is a tidier solution.

But Irix go a step further than that and give you the ability to MOVE the position of the infinity indicator to correspond with a true visual infinity. PLEASE READ the manual before attempting to do this yourself.

So this Irix Blackstone 15mm f2.4 is perhaps the most well-appointed lens I’ve ever come across – but now it’s time for the rubber to meet the tarmac and actually do some testing.

Comparative testing

It made sense to compare the Irix Blackstone 15mm f2.4 to possibly the best known and more expensive lenses in this super-wide lens class, namely the Nikon 14-24mm f2.8 and the Zeiss Distagon 15mm f2.8 ZF2. There seemed very little point in comparing the Irix to the likes of the Rokinon/Samyang 14mm prime as I would expect the Irix to out-perform it by a good stretch, and thus not show how far the Irix ‘punches above its own weight’.

I’ve been wanting a prime to replace the Nikon 14-24mm, especially for night sky photography, for quite some time. To that end I have tried three different examples of the Samyang 14mm f2.8 and found them all terrible with the aperture wide open when used on a 36Mp camera. The images from it might appear okay shrunk down to 1920 x 1080 and run in a time-lapse video, but for full resolution stills and large display prints I have found all three examples I have tried to be inferior in terms of sharpness and coma.

Irix Blackstone 15mm f2.4

So having decided on the two comparison lenses my first test was for vignetting.

Vignette Test Results:

The images below were all produced using the standard DSO Flat Frame production technique of imaging a diffused D65 light source with the lens focused at infinity.

(Click the image to open in a new window and click again to view at full size)

Vignette testing the IRIX 15mm Blackstone lens against the Zeiss Distagon 15mm f2.8 ZF2 and the Nikon 14-24mm f2.8 @15mm. (Click the image to open in a new window and click again to view at full size).

Now before anyone gets ‘all hot and bothered’ about the vignetting on the Irix at wider apertures, here’s where the advantage of a removable lens hood comes into play. Taking the lens hood off after you have produced your image enables you to easily produce a flat calibration frame using an LCP filter – something that the medium and large format photographers have been doing for years. Combining these frames is easy inside the likes of Lightroom, and the process removes all vignetting, colour shifts and dust spots from your images.

Of course, you can produce flat calibration frames for the likes of the Nikon or Zeiss – I do it all the time – but you have to make them in the same manner as I made the test shots above. But it is imperative that you shoot them at the same focus distance, ISO, focal length and aperture as your image frames.

But using the Irix makes the process very simple and it takes just a few seconds to produce a calibration frame which is customized for your composition and lighting levels.

So despite what you might think, vignetting is irrelevant – especially on lenses with a removable lens hood.

Sharpness & Diffraction, Resolution, Chromatic Aberration, Native Lens Color Cast & Contrast Testing.

Please make sure you view these images at 100% magnification by clicking on them.

This test was carried out at a focus distance of 12.5 inches and lacking a proper test bed, getting everything parallel and centered was quite time-consuming I can tell you!

All images shot in manual mode at ISO200 using shutter speeds that rendered a +/-0Ev on the cameras internal meter.

There are some subtle exposure variations between shots from the same lens in each of the three tests which is due to the use of cold cathode lighting, its flicker frequency and the shutter speeds used, but the variation is negligible and for our purposes totally irrelevant.

There has been no sharpening, CA correction, luminance or color noise reduction or other process settings applied to any of the images you see below except for white balance.

The first set of images show the low right optical center 770 pixel square from the D800E raw files. The second set of images show the same 770 pixel square from the bottom left corner of the frame, and the third set that of the top center. I chose the low right center because we are interested in the rendering of the higher lpm (line pairs per millimeter) resolving power of the three lenses being tested. The axial center is located in the middle of the concentric circles:

Sharpness & Diffraction, Resolution & CA, Native Lens Contrast & Colorcast test results.
Image Center Low Right
Camera used: Nikon D800E.

Immediately one or two things are apparent.

The Zeiss is the sharpest at apertures wider than f5.6, and both the Nikon and Irix catch up with it by the time we get to f8.

So above (wider than) f8 the Irix would appear to be less sharp than the Zeiss – but things are never quite so cut and dried as they appear.

The Zeiss is not quite as sharp as you think because it’s got a higher degree of transmitted contrast – something a lot of people would be mistaken in thinking is due to the so-called ‘Zeiss pop’**. If I remove -20 contrast from the Zeiss f5.6 image and equalize the black and white greyscale values in Photoshop, then the difference between it and the Irix at f5.6 appears to be significantly less than we first thought:

Zeiss Distagon @ f5.6 (left0 vs Irix Blackstone @ f5.6 (right) with black point and white point greyscale values in the Zeiss image modified to closely approximate those of the Irix image.

** the so-called ‘Zeiss pop’ is down to sublime MICRO-CONTRAST, and the 15mm Distagon has very little of it. You need to look at Zeiss lenses longer than 25/30mm before you even begin to see it.

And the Nikon exhibits the same tendency, though not as extreme as the Zeiss.

So all in all, from an image center sharpness point of view the Irix has good level of performance.

The Irix seems to consistently produce a ‘warmer’ image at f2.4 than at f2.8 and beyond, which is a bit odd, but again easily correctable in post so not of any real concern – unless you are crazy and shooting jpeg-only of course.

The next observation we can make is image center CA. All 3 lenses exhibit good anti CA in their image centers, but if you look carefully you will see that the best performer is the Irix. The Zeiss is second best, and the most obvious CA can be seen on the Nikon images.

Diffraction:

On the diffraction side of things we can see diffraction begins to show at apertures smaller than f11. But diffraction is caused by the inter-relationship of lens aperture Airy Disc and sensor CoC (circle of confusion). As long as the lens aperture Airy Disc is SMALLER than the sensor CoC, diffraction will not be a problem.

When the Airy Disc and sensor CoC are of equal size the combination of lens and camera sensor is said to be at its ‘diffraction limit’.

These images were produced using a 36Mp Nikon D800E, which is diffraction limited to f14 at best, and more usually f13. Switching out to a 20Mp Nikon D4 I’m diffraction limited to f16 or 18, and on a 12Mp D3 I can get away with f20.

So diffraction has little to do with the lens and everything to do with the camera sensor, and if I had used a Nikon D3 for the above tests then f22 on all 3 lenses would look a lot sharper!

Lens Native Color Cast:

We can also just about see the Zeiss has a vestige of a green cast, and the Nikon a slight blueish one while the Irix stays fairly neutral (other than at f2.4).

The CA/Color & Resolution story takes on a whole different meaning though when we move off-axis and look at the image sides and corners:

Sharpness & Diffraction, Resolution & CA, Native Lens Contrast & Colorcast test results.
Image Lower Left Corner
Camera used: Nikon D800E. (Click the image to open in a new window and click again to view at full size).

Between the Nikon & Zeiss that’s £3500 worth of glass at f2.8 out-performed by a much cheaper lens at f2.4 – gives you something to think about doesn’t it.

Now let’s take a look at the top center:

Sharpness & Diffraction, Resolution & CA, Native Lens Contrast & Colorcast test results.
Image Top Center
Camera used: Nikon D800E. (Click the image to open in a new window and click again to view at full size).

In both of the off-axis comparison tests you can easily tell which lens is the winner in the CA stakes – the Irix, and by a huge margin too.

Yes it does exhibit some CA at the image margins, but far less than the other two lenses.

CA removal can sometimes have a detrimental effect on convoluted edges in your images due to the manner in which it works. Ordinarily these errors don’t have much of a visual impact in your shots, but the larger your sensors pixel count the more edge-halo problems you can experience if you try the sharpen the image, or try to create or apply masks. I shall talk more about this later.

The inherent ‘native’ color cast of the Nikon and Zeiss lenses is plainly obvious in the off-axis test shots, as is the neutrality of the Irix.

Something else you may or may not have noticed in the above 3 test sequences is that the Nikon 14-24mm @ 15mm images all display an increased ‘image magnification’. This is due to excessive FOCUS BREATHING of this particular lens. Focused at such a short distance – 12.5 inches – 15mm on the Nikon carries the same magnification you would associate with perhaps a 16mm or 17mm lens.

Lens Barrelling:

Lens barrelling & angle of view of the Nikon 14-24mm f2.8 @ 15mm
12 feet and f14.

Lens barrelling & angle of view of the Zeiss Distagon 15mm f.8 ZF2.
12 feet and f14.

Lens barrelling & angle of view of the Irix Blackstone 15mm f2.4.
12 feet and f14.

The barrelling test loser is the Nikon – and you can also now see that, even at 12 feet, the focus breathing of the lens is resulting in a wider AoV – check the right edge of the air vent in the brick wall.

So the Nikon – at reasonable working distances – has a wider Angle of View (AoV) than the Zeiss, which in turn is marginally wider than the Irix. I can’t say that I’m particularly bothered by this as the overall effect is minimal.

The Irix has slightly less barrel distortion than the Zeiss and so has to be the clear winner.

Coma Test

Seeing as the Irix originally piqued my interest as a super-wide prime with astro potential I’m really keen on looking at the coma it produces.

What’s Coma Andy and why does it matter to you?

First things first, here is what Coma looks like:

Top Right corner Canon 16-35 USMII at 16mm & f2.8

The artifacts produced by Coma at wide apertures can make certain lenses redundant for astro photography – every single one of those upside down Cylon Warbirds is a star that’s supposed to look like a pin-prick of light.

Coma, or Comatic Aberration, is simply a distortion of off-axial point light sources. The direction of the distortion can be sagittal (parallel to the lens diagonal), meridional (perpendicular to the lens diagonal), or a mix of both.

In the Canon lens above (that was over £1000 worth when new) the coma is strongly meridional which is then pin-cushioned – terrible, and virtually impossible to correct for in Photoshop. Yes, the coma vanishes at around f7/f8, but you can’t use those small apertures when shooting astro.

Contrast the image above to the one below from the Nikon 14-24:

Top Right corner Coma on the Nikon 14-24mm @ 14mm and f2.8

Okay, the Nikon sets the bench mark – the Coma is a fairly even mix of mild meridional and sagittal distortion which can easily be corrected in Photoshop where necessary.

Let me just say that the images above were shot under perfect dark sky conditions. The image below by comparison is most definitely NOT – the sky is full of light pollution and we can’t see the stars at their full brightness, so the next shot is a slightly unfair comparative:

Top Right corner Coma on the Irix 15mm @ f2.8

As I said, due to light pollution we can’t see any of the fainter stars, and the brighter ones look smaller.

And here is the Zeiss 15mm Distagon ZF2 under the same conditions as the Irix above:

Top Right corner on the Zeiss 15mm f2.8 Distagon ZF2 @ f2.8

To be honest, the level of coma in both the Irix and the Zeiss are in no way unmanageable in Photoshop, and so are of little concern. Both are mild in their extremes of the image frame corners, the Zeiss being slightly biased towards sagittal and the Irix perhaps a tiny bit more meridional.

In both lenses the distortion ‘coma tails’ are smaller than the stars diameter and so a piece of cake to remove with a coma brush in Photoshop.

And if you want to know what a ‘coma brush’ is then go and buy my My Complete Guide to Photographing and Processing Night Sky Images.

Light Transmission

When I was doing the light polluted night sky shots I mentioned earlier I became very aware of something I hadn’t really noticed before – a T-stop difference between the Irix and the Zeiss:

Click the image to view larger

A 6 second exposure at the same aperture (f-number) and ISO on the Zeiss is roughly as bright as a 3 second exposure using the Irix.

The middle image is 3 seconds using the Zeiss, and is noticeably darker – I would say that the Irix transmits somewhere between +0.6 and +0.75Ev more light than the Zeiss – which let’s not forget is THREE TIMES THE PRICE!

So, what do I think of the Irix Blackstone 15mm f2.4 so far – bearing in mind that I need to test it for flare and focus breathing. Well, I’m off to Norway for a week and hopefully I’ll get a few seascapes and high country midnight sun landscapes done in between the eagle action – and the Irix is the only superwide I’m packing!

I will conclude my review of this lens on my return from the land of the Vikings, but suffice to say, at the moment I consider possession of this lens a complete NO-BRAINER.

See my UPDATE on this lens HERE.

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Your Monitor – All You Ever Wanted to Know

Posted on March 21, 2017 by Andrew Astbury

Your Monitor – All You Ever Wanted to Know, and the stuff you didn’t – but need to!

I need a new monitor, but am undecided which to buy. I know exactly which one I’d go for if money was no object – the NEC Spectraview Reference 302, but money is a very big object in that I ain’t got any spare!

But spend it I’ll have to – your monitor is the window on to your images and so is just about THE most important tool in your photographic workflow. I do wish people would realize/remember that!

Right now my decision is between 24″ and 27″, Eizo or BenQ. The monitor that needs replacement due to backlight degradation is my trusty HP LP2475W – a wide gamut monitor that punched way above its original price weight, and if I could find a new one I’d buy it right now – it was THAT good.

Now I know more than most about the ‘numbers bit’ of photography, and this current dilemma made me think about how much potential for money-wasting this situation could be for those that don’t ‘understand the tech’ quite as much as I do.

So I thought I’d try and lay things out for you in a simple and straight forward blog post – so here goes.

The Imaging Display Chain

Image Capture:

Let’s take my landscape camera – the Nikon D800E. It is a 36 megapixel DSLR set to record UNCOMPRESSED 14 bit Raw files.

The RAW image produced by this camera has a pixel dimension of 7360 x 4912 and a pixel area of 36,152,320 pixels.

The horizontal resolution of this beastly sensor is approximately 5200 pixels per inch, each pixel being 4.88 µm (microns) in diameter – that’s know as pixel pitch.

During the exposure, the ANALOGUE part of the senor sees the scene in full spectrum colour and tone through its Bayer Array – it gathers an analogue image.

When the shutter closes, the DIGITAL side of the imaging sensor then basically converts the analogue image into a digital render with a reproduction accuracy of 14 bits per pixel.

And let’s not forget the other big thing – colour space. All dslr cameras capture their images in their very own unique sensor colour space. This bares little to no resemblance to either of the three commonly used digital colour management workflow colour spaces of sRGB, AdobeRGB1998 or ProPhotoRGB.

But for the purposes of digital RAW workflow, RAW editors such as Lightroom do an exceptional job of conserving the majority if not all the colours captured by the camera sensor, by converting the capture colour space to that of ProPhotoRGB – basically because it’s by far the largest industry standard space with the greatest spread of HSL values.

So this RAW file that sits on my CF card, then gets ingested by my Mac Pro for later display on my monitor is:

1.41 inches on its long edge
has a resolution of around 5,200 pixels per inch
has a reproduction accuracy for Hue, Saturation & Luminance of 14 bits
has a colour space unique to the camera, which can best be reproduced by the ProPhotoRGB working colour space.

Image Display:

Now comes the tricky bit!

In order to display an image on a monitor, said monitor has to be connected to your computer via your graphics card or GPU output. This creates a larger number of pitfalls and bear traps for the unsuspecting and naive!

Physical attributes of a monitor you need to bare in mind:

Panel Display Colour Bit Depth
Panel Technology – IPS etc
Monitor Panel Backlight – CCFL, WCCFL, LED etc
Monitor Colour Look-Up Table – Monitor On-Board LUT (if applicable)
Monitor connectivity
Reliance on dedicated calibration device or not

The other consideration is your graphics card Colour Look-Up Table – GPU LUT

1.Monitor Panel Display Colour Bit Depth – All display monitors have a panel display colour bit depth – 8 bit or 10 bit.

I had a client turn up here last year with his standard processing setup – an oldish Acer laptop and an Eizo Colour Edge monitor – he was very proud of this setup, and equally gutted at his stupidity when it was pointed out to him.

The Eizo was connected to the laptop via a DVI to VGA lead, so he had paid a lot of good money for a 10 bit display monitor which he was feeding via a connection that was barely 8 bit.

Sat next to the DVI input on the Eizo was a Display Port input – which is native 10 bit. A Display Port lead doesn’t cost very much at all and is therefore the ONLY sensible way to connect to a 10 bit display – provided of course that your machine HAS a Display Port output – which his Acer laptop did not!

So if you are looking at buying a new monitor make sure you buy one with a display bit depth that your computer is capable of supporting.

There is visually little difference between 10 bit and 8 bit displays until you view an image at 100% magnification or above – then you will usually see something of an increase in colour variation and tonal shading, provided that the image you are viewing has a bit depth of 10+. The difference is often quoted at its theoretical value of 64x – (1,073,741,824 divided by 16,777,216).

So, yes, your RAW files will LOOK and APPEAR slightly better on a 10 bit monitor – but WAIT!

There’s more….how does the monitor display panel achieve its 10 bit display depth? Is it REAL or is it pseudo? Enter FRC or Frame rate Control.

The FRC spoof 10 bit display – frame rate control quite literally ‘flickers’ individual pixels between two different HSL values at a rate fast enough to be undetectable by the human eye – the viewers brain gets fooled into seeing an HSL value that isn’t really there!

Here’s why I hate FRC !

Personally I have zero time for FRC technology in panels – I’d much prefer a good solid 8 bit wide gamut panel without it than a pseudo 10 bit; which is pretty much the same 8 bit panel with FRC tech and a higher price tag…Caveat Emptor!

2. Panel Technology – for photography there is only really one tech to use, that of IPS or In Plane Switching. The main reasons for this are viewing angle and full colour gamut.

The more common monitors, and cheaper ones most often use TN tech – Twisted Nematic, and from a view angle point of view these are bloody awful because the display colour and contrast vary hugely with even just an inch or two head movement.

Gamers don’t like IPS panels because the response time is slow in comparison to TN – so don’t buy a gaming monitor for your photo work!

There are also Vertical Alignment (VA) and Plane to line Switching (PLS) technologies out there, VA being perhaps marginally better than TN, and PLS being close to (and in certain cases better than) IPS.

But all major colour work monitor manufacturers use IPS derivative tech.

3. Monitor Panel Backlight – CCFL, WCCFL, LED

All types of TFT (thin film transistor) monitor require a back light in order to view what is on the display.

Personally I like – or liked before it started to get knackered – the wide cold cathode fluorescent (WCCFL) backlight on the HP LP2475W, but these seem to have fallen by the wayside somewhat in favour of LED backlights.

The WCCFL backlight enabled me to wring 99% of the Adobe1998 RGB colourspace out of a plain 8 bit panel on the old HP, and it was a very even light across the whole of the monitor surface. The monitor itself is nearly 11 years old, but it wasn’t until just over 12 months ago that it started to fade at the corners. Only since the start of this year (2017) has it really begun to show signs of more severe failure on the right hand 20% – hence I’ll be needing a new one soonish!

But modern LED backlights have a greater degree of uniformity – hence their general supersedence of WCCFL.

4. Colour Look-Up Tables or LUTs

Now this is a bit of an awkward one for some folk to get their heads around, but really it’s simple.

Most monitors that you can buy have an 8 bit LUT which is either fixed, or variable via a number of presets available within the monitor OSD menu.

When it comes to calibrating a ‘standard gamut with fixed LUT’ monitor, the calibration software makes its alterations to the LUT of the GPU – not that of the monitor.

With monitors and GPUs that are barely 8 bit to begin with, the act of calibration can lead to problems.

A typical example would be an older laptop screen. A laptop screen is driven by the on-board graphics component or chipset within the laptop motherboard. Older MacBooks were the epitome of this setups failure for photographers.

The on-board graphics in older MacBooks were barely 8 bit from the Apple factory, and when you calibrated them they fell to something like 6 bit, and so a lot of images that contained varied tones of a similar Hue displayed colour banding:

An example of image colour banding due to low GPU LUT bit depth.
The banding is NOT really there, it just illustrates the lack of available colours and tones for the monitor display.

This phenomenon used to be a pain in the bum when choosing images for a presentation, but was never anything to panic over because the banding is NOT in the image itself.

Now if I display this same RAW file in Lightroom on my newer calibrated 15″ Retina MacBook Pro I still see a tiny bit of banding, though it’s not nearly this bad. However, if I connect an Eizo CS2420 using a DisplayPort to HDMI cable via the 10 bit HDMI port on the MBP then there is no banding at all.

And here’s where folk get confused – none of what we are talking about has a direct effect on your image – just on how it appears on the monitor.

When I record a particular shade of say green on my D800E the camera records that green in its own colour space with an accuracy of 14 bits per colour channel. Lightroom will display it’s own interpretation of that colour green. I will make adjustments to that green in HSL terms and then ask Lightroom to export the result as say a TIFF file with 16 bits of colour accuracy per channel – and all the time this is going on I’m viewing the process on a monitor which has a display colour bit depth of 8 bit or 10 bit and that is deriving its colour from a LUT which could be 8 bit, 14 bit or 16 bit depending on what make and model monitor I’m using!

Some people get into a state of major confusion when it comes to bits and bit depth, and to be honest there’s no need for it. All we are talking about here is ‘fidelity of reproduction’ on the monitor of colours which are FIXED and UNALTERABLE in your RAW file, and of the visual impact of your processing adjustments.

The colours contained in our image are just numbers – nothing more than that.

Lightroom will display an image by sending colour numbers through the GPU LUT to the monitor. I can guarantee you that even with the best monitor in the world in conjunction with the most accurate calibration hardware money can buy, SOME of those colour numbers will NOT display correctly! They will be replaced in a ‘relative colourmetric manner’ by their nearest neighbor in the MONITOR LUT – the colours the monitor CAN display.

Expensive monitors with 14 bit or 16 bit LUTs mean less colours will be ‘replaced’ than when using a monitor that has an 8 bit LUT, and even more colours will be replaced if we scale back our ‘spend’ even further and purchase a standard gamut sRGB monitor.

Another advantage of the pricier 14/16 bit wide gamut dedicated photography monitors from the likes of Eizo, NEC and BenQ is the ability to do ‘hardware calibration’.

Whereas the ‘standard’ monitor calibration mentioned earlier makes it’s calibration changes primarily to the GPU LUT, and therefore somewhat ‘stiffles’ its output bit depth; with hardware calibration we can internally calibrate the monitor itself and leave the GPU running as intended.

That’s a slight over-simplification, but it makes the point!

5. Monitor Connectivity. By this I mean connection type:

VGA or D-Sub 15. Awful method of connection – went out with the Ark. If you are using this then “stop it”!

DVI – nothing wrong with this connection format whatsoever, but bare in mind it’s an 8 bit connection.

Dual Link DVI – still only 8 bit.

Displayport – 10 bit monitor input connection.

HDMI left, Displayport right – both 10 bit connections.

6. Reliance on dedicated calibration device or not – this is something that has me at the thin end of a sharp wedge if I consider the BenQ option.

I own a perfectly serviceable ColorMunki Photo, and as far as I can see, hardware calibration on the Eizo is feasible with this device. However, hardware calibration on BenQ system software does not appear to support the use of my ColorMunki Photo – so I need to purchase an i1 Display, which is not a corner I really want to be backed into!

Now remember how we defined my D800E Raw file earlier on:

has a pixel dimension of 7360 x 4912 and a pixel area (or resolution) of 36,152,320 pixels.
1.41 inches on its long edge
has a resolution of around 5,200 pixels per inch
has a reproduction accuracy for Hue, Saturation & Luminance of 14 bits
has a colour space unique to the camera, which can best be reproduced by the ProPhotoRGB working colour space.

So let’s now take a look at the resolution spec for, say, the NEC Spectraview Reference 302 monitor. It’s a 30″ panel with an optimum resolution of 2560 x 1600 pixels – that’s 4Mp!

The ubiquitous Eizo ColorEdge CG2420 has a standard 24 inch resolution of 1920 x 1200 pixels – that’s 2.3Mp!

The BenQ SW2700PT Pro 27in IPS has 2560 x 1440, or 3.68Mp resolution.

Yes, monitor resolution is WAY BELOW that of the image – and that’s a GOOD THING.

I HATE viewing unedited images/processing on my 13″ Retina MBP screen – not just because of any possible calibration issue, or indeed that of its diminutive size – but because of its whopping 2560 x 1600, 4Mp resolution crammed into such a small space.

The individual pixels are so damn tiny the lull you into a false sense of security about one thing above all else – critical image sharpness.

Images that ‘appear tack sharp’ on a high resolution monitor MIGHT prove a slight disappointment when viewed on another monitor with a more conventional resolution!

So there we have it, and I hope you’ve learned something you didn’t know about monitors.

And remember, understanding what you already have, and what you want to buy is a lot more advantageous to you than the advice of some bloke in a shop who’s on a sales commission!

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Canon 16-35mm f2.8 Mk3

Posted on December 30, 2016 by Andrew Astbury

Canon 16-35mm f2.8 Mk3

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.

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.

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.

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:

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:

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!

[sciba leftsrc=”https://www.wildlifeinpixels.net/blog/wp-content/uploads/2016/12/1D9A6348.jpg” leftlabel=”Mk III” rightsrc=”https://www.wildlifeinpixels.net/blog/wp-content/uploads/2016/12/1D9A6347.jpg” rightlabel=”Mk II” mode=”horizontal” width=””]

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.

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

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

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:

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.

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.

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:

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

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

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

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

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

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:

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:

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:

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.

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 supporting me via Patreon.

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.

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Canon 5D Mk 4 Auto Focus Performance

Posted on November 24, 2016 by Andrew Astbury

Canon 5D Mk 4 Auto Focus

Canon 5D Mk 4

Like Nikon, Canon never do me any favors!

But I do feel that I must say to the world that it ought to give this camera a bit of a break. It’s had a good mauling in a lot of places, usually by idiots and no-nothings, who keep comparing it to its big brother the 1DX Mk2 – a camera not without its very own set of unique foibles!

The Canon 5D Mk 4 is NOT designed to be a “poor mans” 1DX Mk2.

It’s hardly what I’d call ‘cheap’ in the old purchase price department for starters, so ‘poor mans’ and ‘budget’ are not terms I can easily associate with it.

There are lot’s of things I need to delve into further on this camera to give you guys a fuller picture of the cameras overall performance – most of which is going to involve Calumet or Canon lending me more lenses.

But I can say that I’ve formulated a solid opinion on the Canon 5D Mk 4 Auto Focus performance, and it’s turned out to be a lot better than I’d first imagined.

These are the style of shot that really tells you if your auto focus is working and up to the job:

“Joey” 1/3200th, f7.1, ISO5000

“Joey” 1/3200th, f7.1, ISO4000

But before you can start producing the shots you have to go through the tedious bit of testing the AF first. It was while testing the overall sharpness and accuracy of the AF system that I came across a little problem.

When photographing the old ‘brick wall’ static target I found the system was front focusing by around 40 centimeters at 30 meters. If I added +4 on the AF micro adjustment (using the 500mm don’t forget) then everything was razor sharp.

This didn’t seem right in my eyes – I’ve never felt the need to use micro adjust on Canon gear to achieve sharp focus on a static target – perhaps I’ve just been lucky!

But after testing this body with another 500mm L IS II, and Calumets lens on 3 other bodies, all tests revealed the same necessary +4 adjustment.

The difference is quite marked!

Bare in mind that all these ‘static tests’ MUST be done with the aperture WIDE OPEN (in this case f4).
I always use the high ISO capabilities of a camera to the maximum, which allows me the luxury of shooting at between f6 and f8 to maximise DoF and use a high enough shutter speed to stop the action. Manual exposure with Auto-ISO is my usual method of shooting with long glass. A noisy image that is razor-sharp will ALWAYS out-sell a low noise image full of motion blur!
At f8 hardly any of the ‘poor sharpness’ (above left) is visible in the image because DoF is doubled from 40cms to over 80cms behind the plane of focus at this distance.
If I was to swap out to a shorter lens then the required amount of micro adjustment would be less, and with a longer lens MORE!

However, when we come to photograph the likes of ‘Joey’ we have a BIG problem!

Adding positive micro-adjustment values is basically like adding BACK FOCUS – you are telling the system to focus BEHIND where it perceives sharp focus to be – in other words ‘focus further away’.

So with a head on closing target/subject the resulting AI Servo sequence of frames will all be back focused. The camera will be focusing behind a subject that’s getting closer – it’ll never work!

What we need is the system to move the plane of focus AHEAD of the subject, so that when the shutter opens for the next frame, the subject and plane of focus are hopefully in the same place. This is how PREDICTIVE AF works, and cameras like the 1DX Mks 1 & 2/Nikon D4/4S truly excel at it.

Dialing in an opposite value of -4, and using AF Case 4 settings with Zone AF for the AI Servo sequences of little Joey yielded good results, but the level of consistency was still below what I thought was possible.

And it certainly got even less consistent when I changed to Point Expansion or Point Surround AF modes.

But now I’ve settled on a custom setup that is NOT obtainable on any of the fixed AF cases; TS & ADT both at +2 together with -3 AF micro adjustment:

‘Morgan’ 1/4000th f8 ISO4000 & -3 AF micro adjustment

I’ve just uploaded a new video to my YouTube channel where I discuss the performance of the Canon 5D Mk 4 Auto Focus system, and go through A LOT of full resolution images.

Note, some of you may get bored and think I examine too many images – shame on you! There are 4 sequences, and each one represents around 4 seconds in real time and are a ‘buffers worth’ of shots. So all those boring shots took less than 20 seconds to acquire – I have to show all the shots in a sequence to illustrate the level of consistency, and I show 4 sequences to prove none of them are a fluke – I DO THE JOB RIGHT – unlike some other reviewers!

You can view it at full size by clicking the YouTube icon bottom right once you press ‘play’, but be warned it’s 36 minutes long!

I’m not finished with this camera just yet I don’t think; I must admit that I do quite like it!

Is the Canon 5D Mk 4 Auto Focus capable of better performance than that of the venerable old 5D Mk3 ? Yes, it is.

Is the image quality better than the 5D Mk3 – oh you betcha it is, by a country mile and just like the 1DX Mk2 advantage over the 1DX.

Are the G/T algorithms (ISO), sensor and ADC output better – from what I can see that’s a ‘yes’ too; but then I’ve not done any dynamic range testing yet – kinda hard when the only lens you’ve got is a 500mm!

I’m getting used to the ‘touchy-feely’ screen now, but the fixed 7fps HS frame rate pisses me off a bit, I’d like to be able to drop it to 6 or 5 to the AF system even further.

Take my advice and don’t be impressed with the ‘Duel Pixel Raw’ feature – it’s CRAP. It does absolutely bugger-all apart from slow the camera down and produce massive files that are not worth the time or effort. And you can only ‘work’ them in that clunky DPP software which is a total abomination to try and use!

And old UHS1 SD card tech? The camera would be better with a CF slot in conjunction with a CFast2 slot ‘a la’ 1DX Mk2 – in my opinion of course.

Great Tit. Canon 5DMkIV, Canon 500mm f4 L IS II, ISO 10,000 +4 AF Micro adjustment

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Lumenzia UPDATE

Posted on June 22, 2016 by Andrew Astbury

Lumenzia Update version 1.8.3

There has just been a new Lumenzia update made available today. Existing users need to update this as soon as possible, especially those using the latest iteration of Photoshop CC 2015. The update fixes compatibility errors with the “Combine Tool”.

Anyone who HAS NOT invested a few dollars in LUMENZIA needs to do so – not having it is a fools game!

REMEMBER – Lumenzia is NOT another filter FX set; it’s a tool that helps the uninitiated conquer the fearsome Photoshop skill of Luminosity Masking. It also helps with all sorts of other Photoshop tasks and image improvements.

I’ve been promoting the Lumenzia Photoshop extension for a year now. Over that time it has grown into something that represents even greater value for money than it did in the first place. And it was great VFM then!

Customers can buy and download LUMENZIA by clicking here.

UPDATE: Greg Benz (the plugin author) has launched a comprehensive Lumenzia training course – see my post here for more information.

Check out my other posts about it here, here and here

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Image Sharpness

Posted on April 16, 2015 by Andrew Astbury

Image Sharpness

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

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

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

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

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

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

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

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

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

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

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

Click the images to view them properly.

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

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

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

Or are we?

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

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

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

Guessed which is which yet?

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

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

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

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

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

Wrong…it’s number 1…

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

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

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

So why is one IN FOCUS and the other not?

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

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

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

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

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

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

And a few more things besides…!

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Shameless Plug Number 1.

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

Understanding Canon & Nikon Autofocus

for

Bird in Flight Photography

Click Image for details.

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Wildlife in Pixels – Website News

Posted on April 10, 2015 by Andrew Astbury

Wildlife in Pixels – main website updated & other news.

So I’ve just spent the last 4 days slaving away over an old version of Dreamweaver (CS4 no less) updating the rather tired and untidy looking main website.

With a not insignificant amount of valuable input from my learned friend Steve Kaluski, and the (new to this old fart) discovery of in-line css rules, I’ve managed to come up with what I think is a cracking new look for the website that’s far less cluttered and messy!

The new site landing page.

That’ll do for the rest of this year at least, and I think it looks epic – what say you guys?

I’ve updated the image gallery using Juicebox – whether I leave the “share” and image page display options live I’ll decide over the next few days. But the gallery is a lot less “clunky” than it used to be, and looks pretty good on an iPhone too.

The new website gallery.

Important News about Norway Workshops for 2016.

I booked two trips over in Norway for 2016 about 4 weeks ago – one in February 2016, which is my usual winter haunt of Flatanger.

Norway Winter Eagles Tour February 2016. Click to view website page for this tour.

And the second trip, scheduled for September 2016 is over to Dovrefjell for the Musk Ox and Arctic Fox, followed by 3 days of Eagle photography from the boat.

Norway Tour September 2016. Click to view website page for this tour.

In the very short space of time these trips have been publicised, the uptake has been awesome – the February trip is provisionally full and; again provisional, there are only two places left on the September trip.

At the bottom of new Norwegian Workshops page – HERE – you’ll see that I’m running a ‘standby’ email link. If you are interested in going on this list just drop me an email via the link. I’ve never had a cancellation for any reason as yet – but just in case it does happen then I can let you know. Meanwhile, visit the workshop pages themselves and get a flavour of what they are about.

Anyway, thanks for reading this short missive and if you have a chance hop along to the main website and give it the “once over” as your opinion matters!

View Autofocus Points in Lightroom

Posted on February 1, 2015 by Andrew Astbury

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

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

Follow the installation instruction to the letter!

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

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

You will see this sort of thing:

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

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

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

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

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

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

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

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

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

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

Cheers to Malc Clayton for bringing this to my attention.

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Canon 1Dx Sensor Noise

Posted on January 30, 2015 by Andrew Astbury

What seems an age ago now I did a two-day workshop for Calumet at Drummond Street in London, and a chap turned up there armed with a Canon 1Dx PLUS a 200-400 f4. The lens had only just been launched, and he’d been out and spent a truck-load of cash on both lens and body.

Yours truly was all over him like a severe rash, and I ripped it from his poor old fingers, stuck it in Case 2 and dived outside and started ripping through frames of vehicles passing the store!

I was smitten from that very moment – but it was weird all the same. I was joyous at how the lens and camera performed; pissed off that I didn’t own it; and seething at Nikon AF and the poor distance performance of their own 200-400.

Not that Nikon is crap – far from it; it’s fantastic – but this was just SO much better, and child that I am, THIS was what I should be using and all else was just pants.

Begrudgingly I handed the old chap his camera back, satisfied my dour mood with a cursory “not bad….” and carried on with the workshop.

Later in the day I stuck the images I’d shot with the Canon 1Dx into Lightroom on the 27″ iMac I use for workshop presentations – and was immediately a little happier – they looked “iffy” to say the least!

The Nikon 200-400s’ distance resolution problem has always hacked me off – 10m or less it’s epic, but 75m and further I hate it, and in between well, sometimes I like it and sometimes I don’t. And it’s bad with teleconverters, it really is…

Scanning through all the Canon 1Dx shots I was still amazed by the lens – it was delivering tack sharp high-resolution images at all focal lengths and distances, with and without teleconverter; basically it was kicking the Nikon into the last century simply by NOT displaying ANY of the same faults.

But I was having to look past – in comparison to Nikon – a thin veil of sensor noise, and I was also aware of a reduction in sensor Dynamic Range when I looked at the shots and noted the popped highlights that experience told me my Nikon wouldn’t produce.

Since then I’ve had a few more occasional chances to use the lens and body, and my results have continued to generate the same response – great lens, shame about the sensor IQ; but I’ve always been using other folks cameras and you don’t like to mess about with them too much, so I have always assumed that things “could be made a bit better” with some fiddling about.

Last year, hand on heart, I can honestly say that I was responsible, in whole or part, for at least 6 sales of Canon 200-400’s to existing 1Dx owners, and the lens-envy has always been there when they’ve been and bought it.

Since the first day I handled the lens I’ve been of the mind that it would be the ultimate lens for my Eagle workshops in Norway. I was thinking of trying to take one, plus the required 1Dx, over there in June last year; but seeing as the my clients were all Nikon I thought I’d best not!

But I have a “mixed bag” of clients booked for my Winter trip in a couple of weeks time, so seeing as I was of the mind that a few folk owed me a few favours…..

Upshot is that for the last two weeks, thanks to Reece Piper at Calumet, I’ve had a Canon 1Dx sat in my office; and many thanks to my favourite Geordie lass June Lown, a 200-400 f4 to go with it.

When I picked up the 1Dx from Calumet I swiped a 100mm f2.8 macro while I was at it, as I had been tasked with a high speed action shot featuring makeup brushes and I thought we’d go nuts and do the shot whilst exploring the 1Dx in a bit more depth.

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

Prior to picking up the Canon 1Dx I’d done a few test shots on my own Nikon gear just to get the lighting and flash timing sorted out, but I’d been using some different brushes:

Okay, so here is the base .CR2 raw file for the finished image:

Base .CR2 raw file

Now, I’m going to get to the point of this post topic!

As a standard retouching procedure on this type of shot I always overlay a custom Curves Adjustment layer with a sine-wave curve – it helps show up all those little imperfections you can’t see when you view the image without it:

Custom Curve for retouching

The main purpose in this particular case is to check for dark imperfections in that black background – yep, proper retouching is all about the minutia if you want perfection.

I’m trying to put together a video course on retouching that’ll be available in my store a little later this year – email me for details

Because the powder velocity is so damned high as it leaves the brush bristles I needed 1/32nd output power on the SB800s in order to freeze absolutely every grain of powder, so the shots(both Nikon and Canon) were at 400 iso just to give me a working aperture of f14.

When checking the test shots they looked like this with the customised Curve Layer:

Nikon D4 400 ISO test shot with custom curves layer.

Nikon D4 400 ISO 1/250th @ f14 test shot with custom curves layer.

Check out how clean the black background is.

So now all we do is swap the brushes, and change from Nikon D4 to the Canon 1Dx – I make no changes to either the lights or the background, and the exposure settings are exactly the same – 1/250th, 400 ISO, f14 – and I’m expecting gold…

But throw the CR2 file into Photoshop and stick the custom curve over it to see the comparrison:

Canon 1Dx 400 ISO 1/250th @ f14

Sweet Jesus………….!

Now don’t run away with the idea that it’s the “normal” noise you think of – luminance noise. In fact from that point of view it’s no better or worse than the Nikon D4 sensor.

But what you can see here is PATTERN NOISE/READ NOISE – see my Sensor Noise post from a while ago HERE

Don’t get me wrong, you can barely see it at 100% magnification, and a lot of folk won’t notice it AT ALL:

Canon 1Dx/Nikon D4 comparrison at 100% magnification viewed normally.

Canon 1Dx/Nikon D4 comparison at 100% magnification viewed normally. CLICK to view larger

But if you want BIG prints, or you sell your images for stock, then you need to check them a lot more thoroughly at higher magnifications:

Comparison at 400% magnification CLICK to view larger

At 400% the noise is just about visible – because it’s a dark error/fault on a basically slightly darker background. But keep it at 100% and put the custom curve over it and:

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

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

…now you can see what you have got to take care off in retouching.

Got a 1Dx? Then this pattern noise is in YOUR images – FACT.

But if the image has a more “normal” tonality to it then it certainly won’t be obvious to you – but it’s there nevertheless. Just try looking in your shadow areas.

Why the 1Dx sensor should be so much noisier than the D4/D4S is beyond me to be honest. Yes I know it’s an older mark, but the then current Nikon D3 and D3S were far better than this; in fact they were, and still are, only marginally worse than today’s Nikons for pattern noise.

In reality the images are of course eminently usable – as the millions of 1Dx images used daily world-wide testifies; but they do need a teeny bit more effort when processing than files from a top-end Nikon camera, if the final images are to have the same degree of quality in terms of “clean-ness of file”.

There is also the question of a clipped Dynamic Range, but that’s an easy walk-around in most cases – neither Highlight Tone Priority or Safety Shift are the answer though IMO; the former just under-exposes the shot, and the latter drives me nuts, though it’s a damnably good idea in principle.

So this noise thing truly is my ONE AND ONLY gripe about this camera – up until this last week I had a few others based solely on my usage of other folks cameras, but those are now well and truly GONE.

On the “pros & cons” side of things, noise and clipped dynamic range are my only cons, and there are many pros that cancel them out – the real big one for my is the autofocus system which, at least when used with the new(ish) 200-400 and the latest firmware, is truly EPIC and seriously kicks Nikon into a cocked hat in terms of tractability, speed, accuracy and user control.

I’m working on a large pdf document all about autofocus with both Nikon D4/D4S and Canon 1Dx bodies that has wildlife photography and long lenses as the main bias, but it will give a lot of valuable information and knowledge to non-wildlife photographers and 5DMk3 owners as well. Again, email me for details – BUT IT WON’T BE FREE!

If I had the dough I’d buy a 1Dx and a 200-400 f4 tomorrow – perhaps I’d even dump Nikon all together for long lens action/wildlife photography.

But I haven’t, so unless a miracle happens and Canon suddenly feel like sponsoring someone who actually “knows about stuff” then there’ll be tears when this rig has to go back I can tell you…:(

Would I dump Nikon for all my photography where speed and autofocus are not required, like macro or landscape – not on your bloody life!

Many thanks to Reece Piper & Calumet UK, June Lown, and Chuck Westfall of Canon USA

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Lens Review – Irix Blackstone 15mm f2.4

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Vignette Test Results:

Sharpness & Diffraction, Resolution, Chromatic Aberration, Native Lens Color Cast & Contrast Testing.

Lens Barrelling:

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The Imaging Display Chain

Image Capture:

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1.Monitor Panel Display Colour Bit Depth – All display monitors have a panel display colour bit depth – 8 bit or 10 bit.

3. Monitor Panel Backlight – CCFL, WCCFL, LED

5. Monitor Connectivity. By this I mean connection type:

Canon 16-35mm f2.8 Mk3

Canon 5D Mk 4 Auto Focus Performance

Lumenzia UPDATE

Lumenzia Update version 1.8.3

Image Sharpness

Image Sharpness

Shameless Plug Number 1.

Understanding Canon & Nikon Autofocus

for

Bird in Flight Photography

Wildlife in Pixels – Website News

Wildlife in Pixels – main website updated & other news.

Important News about Norway Workshops for 2016.

View Autofocus Points in Lightroom

Canon 1Dx Sensor Noise

Many thanks to Reece Piper & Calumet UK, June Lown, and Chuck Westfall of Canon USA

Please consider supporting this blog.

Kamagra Oral Jelly Nz – Worldwide Delivery (1-3 Days)

Kamagra Oral Jelly Nz – Worldwide Delivery (1-3 Days)

Focus Scale & Focus Locking Ring:

Vignette Test Results:

Sharpness & Diffraction, Resolution, Chromatic Aberration, Native Lens Color Cast & Contrast Testing.

Lens Barrelling:

Share this post:

The Imaging Display Chain

Image Capture:

Image Display:

1.Monitor Panel Display Colour Bit Depth – All display monitors have a panel display colour bit depth – 8 bit or 10 bit.

3. Monitor Panel Backlight – CCFL, WCCFL, LED

5. Monitor Connectivity. By this I mean connection type:

Share this post:

Share this post:

Share this post:

Lumenzia Update version 1.8.3

Share this post:

Image Sharpness

Shameless Plug Number 1.

Understanding Canon & Nikon Autofocus

for

Bird in Flight Photography

Share this post:

Wildlife in Pixels – main website updated & other news.

Important News about Norway Workshops for 2016.

Share this post:

Share this post:

Many thanks to Reece Piper & Calumet UK, June Lown, and Chuck Westfall of Canon USA

Please consider supporting this blog.

Share this post:

Kamagra Oral Jelly Nz – Worldwide Delivery (1-3 Days)

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