Custom Camera Calibration for Adobe’s Raw Process Engine
When Thomas Knoll created Adobe Camera Raw there was no universal Raw processor that worked with the majority of digital cameras. Camera manufacturers had their own software to support only their own cameras, and for the most part, it was pretty dreadful. There were a few third party applications that were attempting to work with the major camera brands but nothing like Adobe’s offering which rapidly became the standard against which everything that followed would have to compete. Today there are several different Raw processors, and each has something to offer to their users, but ACR dominates with a much larger user base, due in large part to its integration with Photoshop, and a superior interface. ACR also supports more cameras than most of the competing software, and manages to update rapidly to support the newest cameras. To achieve this support for new cameras, without the help of the camera manufacturers engineering staff, Adobe had to develop a method of calibrating ACR to generate color accuracy with a wide range of different sensors. Initially, this method was only available to Adobe technicians, and was used only to generate support for the different cameras as they became available. Eventually Adobe made their DNG Profile Editor available as free beta software. This little application can be used to build a custom ACR calibration profile that can be used inside ACR to support your specific camera sensor with a more accurate color rendering than the default profiles that come with ACR. This collection of default profiles can be accessed from the Calibration tab in ACR as shone below…
DNG Profile Editor for Mac
DNG Profile Editor for Windows
DNG Profile Editor Documentation
For some odd reason Adobe has never made this software widely available – you really have to hunt for it to find it. At any rate, some time after the software was introduced, X-Rite developed a calibration software of its own, available as part of its ColorPassport package, but also available as a free software download – you can get it here:
ColoChecker Passport application – I believe this is the Mac version, you can probably download the Windows version from X-Rite’s support page here:
ColorChecker Passport Support – click on the support tab and then on the software downloads to see the application and the Lightroom Plugin.
Both the Adobe DNG Editor and the X-Rite ColorChecker Passport application generate a special dng profile that can be used in ACR. Both also utilize the X-Rite 24-patch ColorChecker target for calibration.
The X-Rite software is very simple and straightforward, you run it on a DNG file and it generates a profile and saves it into the appropriate place for ACR access. Adobe’s DNG Editor is much more robust and it offers editing functionality so you can tweak the profile to your liking – I offer some detailed instructions for such tweaking for better skin tones in my Skin book.
There is another camera calibration application offered by Datacolor. This also works with ACR & Lightroom but Datacolor takes a different approach. Instead of generating a dng camera profile, The software creates a Hue-Saturation-Lightness preset, that can be saved as part of your personal camera default inside ACR or Lightroom. The beauty of this approach is that camera calibration is not limited to RAW files, you can calibrate to jpegs, and even video! This software does not use the X-Rite ColorChecker target, for obvious reasons, so they provide their own version of the target known as the SpyderCheckr that contains essentially the same color patches in a slightly different layout, plus an additional 24 patches with other colors. The software comes with the SpyderCheckr, and since you have to use it with their target there’s no point in me offering a download link – you’d still need to purchase the target, even if you already have a ColorChecker target. The rest of this post is devoted to a comparison of all three systems, along with my test results, based on measuring the lab color values of an image of the X-Rite ColorChecker rendered through the different profiles and presets, compared to X-Rite’s published values. You can find X-Rite’s colorimetric values for the ColorChecker here:
As far as I know Adobe Camera Raw/Lightroom is the only RAW processor software that offers custom calibration options, with Datacolor’s additional support for Phocus, Hasselblad’s raw processing software, as the only exception.
The Software in Use
To get your target file into the SpyderCheckr software, you can simply initiate an “Edit In.. ” selection, as shown.