At long last, here’s the comparison of color rendering promised several weeks ago – between work and the display board in my main PC failing, this has taken longer than I’d expected. This post compares the color rendering of Lightroom, Aperture and Capture One versus a synthetic test image. That image was created by taking the raw image from a Leica M8, which is in DNG format, and then replacing the contents of the image with a synthetic version of a GretagMacbeth 24-patch color chart. This can be done because DNG format files contain all the color calibration information that’s required to go from the Camera’s raw image space to a real image in the two ColorMatrix matrices. So the synthetic image is built by taking the l*a*b* color values for the GretagMacbeth test chart, and reversing the calibration matrixes in the Leica DNG file. This, btw, is being done using a modified version of CornerFix – I’m currently debating whether to include the synthetic image creation functionality in the next official CornerFix release.

The synthetic test image is what a “perfect” M8 would show. But “perfect” here means an M8 that matches Leica’s calibration matrixes. However, there is no one single best calibration for a real camera. Pretty much all camera calibration is done via a three by three matrix. Using that, you can dial in any three particular colors exactly. So, for example, you can get the red, blue and green patch on the GretagMacbeth chart down to the last decimal point. If sensors were perfect, that calibration would also mean that every other patch would also be calibrated. However, in a real sensor, there are a whole lot of imperfections – among other things, the filters in the Bayer matrix aren’t ideal, so colors bleed between each other, and the sensitivity of the sensor itself varies with the frequency of the light striking it. So, even if you dial three patches in perfectly, the others will be out. So practically, what camera manufacturers and raw developer software writers have to do is to find a calibration that is a compromise across a whole range of colors. However, because people are more sensitive to certain colors being out (e.g., skin tone, foliage, etc) that compromise is often weighted in favor of the sensitive colors.

The M8 test images can be found here: http://chromasoft.googlepages.com/referenceimages

The charts below show the difference between the theoretical color values that we should see for a selection of six of the more important color patches, and what we actually get. So, for example, if the red bar of the “Cyan patch” shows a value of -5, that means that the actual measured value of the R component of the RGB values as read out by the software in question was 5 units less that the theoretical value as shown in the spreadsheet I discussed in the last post. In all cases, the scale is 0 to 100.

First up is Lightroom. It shows minimal deviations from the theoretical values – all the values are within 3 units. But this shouldn’t come as a surprise – Lightroom internally uses the exact same color model as the DNG file, and we know that Lightroom uses exactly the same color calibration as the Leica DNG’s have embedded into them. The minor deviations that we seeing are really just slight imperfections in the tone curve and in the color temperature interpolation process that Lightroom uses.



Next up is Aperture. There are three Aperture graphs, the first for Aperture V1.5.4. In addition I also have graphs for Aperture 2.0, which came out a few days ago. Aperture 2.0 provides four “Raw Fine Tuning” settings, “1.0”, “1.1”, “2.0” and “2.0 DNG”. I checked, and color rendering from the old 1.5.4 and what you get by setting “1.1” in 2.0 are indeed identical. Firstly, all of the Aperture settings have lot less green in the red patch than Lightroom, and less red in the blue and cyan patches. The 2.0 results are not much different to the 1.5 results; a little bit less red in the blue patch, a bit less green in the red patch, but far less blue in the yellow patch.


The “2.0 DNG” setting is more interesting. There doesn’t seem to be much documentation on what it does – the Apple aperture site itself is silent on the subject, and various third party sites have words to the effect of “changes to the image using the 2.0 DNG converter are made based on the DNG specification of the file”. This implies that rather than using the Aperture color conversion parameters, setting the DNG mode will give you the colors as set by the ColorMatrix values embedded in the DNG. As it turns out however, that’s just not the case – if it were, we’d see values that looked like Lightroom, but what we see are just some subtle changes to the “2.0” profile. Although visible if you change the setting on the fly, the change is actually more subtle than the change between 1.5 and 2.0.




Finally, there is Capture One. During the course of this process, Capture One 4.0.1 came out; the results shown here are for 4.0.1, but they are identical to those for 4.0; as far as I can tell, no changes have been made to color rendering between versions. Capture One provides two profiles, one Generic, and one UVIR, designed to match to the M8’s color rendering when mounted with a UVIR filter. While the differences between these two are there, they are quite subtle. Overall however, there are significant differences to the rendering of either Lightroom or Aperture. Capture One shows less red for most patches, especially the red patch, but more red in the cyan patch. Finally, there is generally somewhat less saturation for most colors. This is broadly consistent with most people’s views on Capture One’s rendering as being “less red” than Lightroom.

In the next post I'll show the same charts for actual rather than synthetic images.
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Good news in a difficult year - all the macOS apps that I support - AccuRaw EXR, AccuRaw Monochrome, pcdMagic, CornerFix, dcpTool (both the GUI and command line version), DNG cleaner and pcdtojpeg - now are all available with native Apple Silicon versions for blazing fast performance on Apple's new
There's a whole slew of new camera support, including for Canon's new CR3 format.

Updates of AccuRaw EXR, AccuRaw Monochrome, PhotoRaw are now available on the Apple App Store.
pcdMagic for Windows - the only currently available app that can convert Kodak Photo CD images with correct color and at full resolution - is now available on the Microsoft Windows Store.
As usual when new Leica cameras come out, I took a quick look inside a DNG from one of Leica's new Leica CL  cameras:

The camera name shows as "LEICA CL" The image data is 14-bit. There is no compression used in the DNG I looked at.  The DNG version is 1.4, with a "backward version" of 1.3.
Those of you that have read the Leica M10 raw file analysis post will know that M10 DNGs have more baggage in them that is typically the case for a Leica DNG. I've put together a little app to clean them up, called DNG Cleaner (Mac only for the moment).
AccuRaw users might have gotten a bit of a surprise recently - AccuRaw has turned into AccuRaw EXR, and is now at version 3.

The reason for the name change is that the focus of the AccuRaw product has changed a bit, based on what users were actually doing with it.
Good news - AccuRaw, AccuRaw Monochrome and PhotoRaw now have support for the compressed raw format that Fuji use in the new GFX 50S. Previous versions of AccuRaw/PhotoRaw had support for the regular uncompressed RAFs, but not the compressed version.
Updated: AccuRaw and PhotoRaw now have support for compressed and uncompressed RAFs.

For those that have been asking me about AccuRaw and Fuji GFX 50S support, I'm pleased to say that the version on the App Store as of today has support, although only for uncompressed RAFs.
As usual when new Leica cameras come out, I took a quick look inside some DNGs from one of Leica's new M10 cameras. Usually, there's not much to see with Leica DNGs - they are typically text-book vanilla DNGs. But with the Leica M10, things are bit more interesting.
AccuRaw EXR is a new version of AccuRaw with support for HDR (High Dynamic Range) images in OpenEXR format. OpenEXR is a high dynamic-range (HDR) image file format developed by Industrial Light & Magic for use in computer imaging applications that uses floating point data.
For those eagerly awaiting the opportunity to be able to process Olympus OM-D E-M1 II raws, the latest version (4.4.2) of PhotoRaw has support, including for the 80 megapixel raws. AccuRaw and AccuRaw Monochrome support will follow in a day or two in version 2.5.1.
New versions of PhotoRaw and AccuRaw became available on the App Store today with support for the new Canon EOS 5D Mark IV.

New to the Canon EOS 5D Mark IV is what Canon are calling ‘Dual Pixel Raw’.
Good news - AccuRaw, AccuRaw Monochrome and PhotoRaw now have support for the compressed raw format that Fuji use in the new X-Pro2. This is thanks to Alexey Danilchenko and the folks over at LibRaw, who reverse engineered the format, and published the results in open source form.
Yes, AccuRaw and PhotoRaw now supports the Nikon 5, all ISO 3,280,000 of it. The new versions are already available on the App Store.
LFI has recently published an article stating that the sensor in the new Leica M262 differs from that in the older Leica M240. This has generated a fair amount of comment on various forums because the M262 is, at least in principle, just a simplified version of the M240.
Mostly, I use this blog to write about photography related issues, but today I'm making an exception, and writing about email apps. Apologies to regular readers, but never fear, normal service will resumed soon.

Email is important to me.
CornerFix was one the the first imaging apps that I wrote. Written originally for the Leica M8 to fix the M8's "pink corners" problem, it corrects for vignetting, both in luminance and in color dependent form. In photographic circles, this is known as "flat fielding".
I've just found out that, to my regret, Photosmith has ceased development. In short, Photosmith allowed images to easily be uploaded to an iPad, sorted, rated, and the ratings etc transferred to Adobe's Lightroom.
(Edited 23 October to include information on how M lenses are handled.)

As usual when new Leica cameras come out, I took a quick look inside a DNG from one of Leica's new Leica SL (Typ 601) cameras, using one of the new Leica L mount lenses:

The camera is using what appears to be production softwa
Affinity Photo isn't one of my products, but I have been following it closely, and trying out the betas as they came out. It is now out of beta, and I know that a lot of readers of this blog are looking for alternatives to being forced onto the Creative Cloud model.
As usual when new Leica cameras come out, I took a quick look inside a DNG from one of Leica's new Leica M Monochrom (Type 246) cameras:

The camera is using what appears to be production software - version 1.0.0.4. The camera name shows as "LEICA M MONOCHROM (Typ 246)" The image data is 12-bit.
I don't often talk about pcdMagic because, well, there's seldom much new to say about it. For those that don't know, pcdMagic is my software package for converting old Kodak Photo CD images to modern formats.
PhotoRaw version 4.2.1 is now available on the Apple App Store with new camera support including the Sony A7 II (ICLE-7M2), Sony QX1 (ICLE-QX1), Panasonic DMC-CM1, Pentax K-S1, Olympus E-PL7, Fuji S1, Kodak C330, Leica D-Lux (Type 109), Leica V-Lux (Type 114), Samsung NX300M, Samsung NX3000
I previously wrote about a nasty bug in iOS 8 that prevented PhotoRaw from accessing any images that were shot as raw+JPEG.
While Adobe's DNK SDK has been a great asset for the imaging world, allowing all sorts of useful open source software, including my CornerFix and dcpTool packages, as written it only supports Windows and OS X.
So you can stop emailing me :)

The versions of AccuRaw and AccuRaw Monochrome on the App Store as of this morning (V2.2.8) have support for the Canon 7D Mark II, Canon SX60 HS, Canon G7 X and Fuji X100T.
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Author of AccuRaw, PhotoRaw, CornerFix, pcdMagic, pcdtojpeg, dcpTool, WinDat Opener and occasional photographer....
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