In this post, I’ll look at the color response of Capture One, Lightroom and Aperture against an image of an actual GretagMacbeth test chart, as cteated on a Nikon D80, rather than the Leica M8 I used in the previous post. As was the case last time, I first adjust the contrast and exposure setting on each program to exactly match expected values of the lightest and darkest monochrome patches on the GretagMacbeth chart. This exactly matches the exposure of the real images to the effective exposure of the synthetic image. As was the case for the synthetic images, all the test results are on a 0 to 100 scale, and represent the difference between the expected value as derived from the color values of the GretagMacbeth chart and the actual values measured. 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.

In the case of Lightroom, relative to the deviations in the M8 actual image from the last post, we see less negative deviations overall, indicating more saturated colors, and a significantly more saturated red patch. However, overall the picture is relatively similar to that of the M8. This starts to imply that differences in color rendering really are more to do with the raw conversion software, and less to do with different cameras.



Aperture shows a somewhat different picture. The 1.1 rendering of the M8 showed some large positive spikes in the blue component of several patches, especially the yellow patch. This doesn’t appear on the D80 rendering. However, the red component is the cyan patch is quite negative. The 2.0 rendering shows considerable change relative to the previous V1.1. Firstly, most of negative deviations have gone – the largest negative deviation anywhere is in the red component of the cyan patch, but even this is well down from the previous value. Overall, the 2.0 D80 rendering appears significantly better controlled than the previous version.



Capture One is an interesting case. At a first glance, it appears that the rendering is simply a considerable distance away from the theoretical values, almost all color components appear to be greater than the theoretical values would indicate. The peak deviations are over 20 units, in sharp contrast to Capture One’s rendering on the M8 image, in which the deviations are of the order of 10 units. However, a closer look shows that what has actually occurred is that the pattern of deviations has remained very much the same, but that their magnitude has grown, and been offset in a positive direction. What this amounts to is that the image is considerably brighter overall. This is a strange result, and one that I’ll come back to in my next post.

For the moment ignoring the issue of the Capture One brightness, we can draw two conclusions at this point:

  1. Most of the color variation that we see appears to be due to variations in the calibration of the raw converters, rather than variations between camera brands. The Lightroom M8 and D80 color renderings look a more alike than, for example, the color renderings of the M8 using Lightroom and Capture One.
  2. Aperture 2’s color rendering appears to have been significantly improved, at least in a technical sense, relative to the previous versions of Aperture.
0

Add a comment

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 "M1" processor. Download are in all the usual places.

Enjoy.

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.

This great news for users:

The Windows Store version has a free trial mode that allows the app to be tested without any commitment. The Windows store handles all updates automatically. There's no need to keep track of license codes. The Windows store only supports the latest versions of Windows 10.
2

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. There is a reason for this - DNG 1.3 allows for opcodes, which Leica use for lens correction.
2

So finally, after many years of searching, I have an answer to the question that torments all who go down the digital color rabbit hole.

This is from XKCD, brought to my attention via an article on the Digital Transitions website about the Phase One IQ3 100mp Trichromatic.

Back in January, when the new Leica M10 was introduced, there were claims that the improvement in dynamic range from the Leica M240 to the M10 was of the order of 1.5 to 2 stops.  At the time, I wrote that just by eyeballing the published images, I believed the improvement to be "closer to 0.5 stops than 1.5-2".

Much to my surprise, given what I had thought to be just a basic explanation of why dynamic range is a tricky concept, the post generated a lot of push-back. And I mean a LOT.

dcpTool has been available for quite a while as a command line application for Windows and the Mac. But now it available in the form of an easy to use Mac app, with powerful batch processing capabilities. dcpTool for the Mac is available from the App Store.

dcpTool allows you to:

Decompile DNG Camera Profile (DCP) files in XML. The XML can then be read and edited with a simple text editor. Recompile edited XML into DCP files Remove "Hue twists" from camera profiles.
11

Many cameras embed lens corrections into raw the raw files that they produce. Generally, that's a good thing - straight lines stay straight, etc. For an example of lens corrections in practice, take a look at this post about the Leica SL.

But, as the saying goes, "there is no free lunch". Lens corrections also have some downsides:

Lens corrections result in a small reduction in sharpness.

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. AccuRaw has always been focussed on having highly linear color response, with no "hue twists" or other surprises in the color rendering.
1
Popular Posts
Blog Archive
About Me
About Me
My Photo
Author of AccuRaw, PhotoRaw, CornerFix, pcdMagic, pcdtojpeg, dcpTool, WinDat Opener and occasional photographer....
Loading