Just before the Christmas break, I decided to spend some time over the holidays comparing Adobe’s Photoshop Lightroom, Apple’s Aperture and Phase One’s Capture One raw developer/digital asset management products. By way of background I’ve been a Lightroom user since the earlier betas, and really like Lightroom’s workflow management. But I’ve never been happy with Lightroom’s color rendition, but have also not had the time to really dig into why I wasn’t getting what I wanted. But by just before Christmas, I was sufficiently frustrated that, despite what I like about Lightroom, I was in “there’s got to be a better way than this” mode – ready for change.

Now one person’s great color rendition is another person’s nightmare, so there isn’t any point in trying to just play with the sliders till something nice comes out – at least not for me. Also, on some products there eighteen sliders, all of which interact. I accept that there may be people out there that can look at an image, move a few sliders, and get what they want, but that isn’t me. So what I’ve chosen to do is to look at color rendition in a more “scientific” way; and ask three questions:

  1. How close is the default rendition of each product to a 24-patch GretagMacBeth color checker?
  2. How easy is it, using each product to calibrate the rendition to as exactly as possible match the theoretical values of the GretagMacBeth test chart, as printed on the instruction sheet that comes with the chart?
  3. How usable is the calibration that I’ve created – is it easy to transfer to other images, how sensitive is it to changes in exposure settings, etc.

At least, while calibrating to to a GretagMacBeth chart doesn't mean I'll have "good" color, at least it's a consistent starting point. And yes, accepted that questions 1 and 2 are fairly simple and objective questions, but that question 3 starts to get more subjective.

As perhaps I might have expected this turned out to be a far more complex process than I’d thought, and eventually pulled me into comparing the three products quite a bit more broadly, for example, as regards the performance of their Bayer interpolation engines.

For the record, the software versions used for this comparison were:

  • Lightroom 1.3.1 Camera Raw 4.3.1
  • Aperture 1.5.4 and 2.0
  • Capture One 4.0.14154.14152 and 4.0.1.14900.14887

Now the first issue that comes up when trying to do this is a simple one - given that, for example, the skin patch on a GetagMacBeth cart has the l*a*b* color values of (65.711, 18.13, 17.81), what does that actually mean in terms of the RGB values that we should expect to get from the cursor read out in each program. A little of experimentation will show that this isn't a simple question.

Actually there are two issues with trying to calibrate imaging software - in what units is the readout, and secondly what adjustments are being applied to the image. Typically, when a raw developer loads a TIFF file, it does so without adjustment, but usually applies some kind of tone curve when loading a raw file.

The readout units for the programs that I've calibrated are:

  1. Lightroom: Melissa RGB - Melissa RGB is the combination of the ProPhoto primaries and the sRBG gamma curve, Also known as "bastard RGB", as it's the bastard child of ProPhoto and sRGB.
  2. Aperture: Wide Gamut. (Note: this was correct at the time this post was originally written. But see the comments this year below - its now Adobe RGB. However, the color rendition information is still correct)
  3. Capture One: Capture One uses whatever color space is set as its output space, so you can set it to any ICM profile you have. For a bunch of ICM profile you can use, see my ICM Profiles page.

The adjustments made by default are more complex - generally, each raw developer has its own tone curve, and also its own default brighness settings.



This is the graph of the ACR 3 default tone curve, as extracted from the Adobe DNG toolkit - it shows the flatting at the top and bottom of the curve, and also the default brightness setting



What I've done to get real tone curves from the packages I'm looking at is to use the monochrome stepwedge reference image (shown above, and available in DNG format on my Reference images page) to work out what the tone curve is.

In part 2, I'll show those curves.

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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 "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.
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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.
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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.
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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.
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