Get more accurate color with camera calibration
The theory of 'Marginal Gains' states that if you make tiny improvements in all aspects of your performance, then these improvements will all add up and create a significant overall improvement. The theory of Marginal Gains can also help with your photographic workflow.
As a travel photographer, I shoot a lot of pictures on a wide variety of subjects. On a recent two day trip to Belgium I came back with well over two thousand pictures, for example. If you're the sort of photographer who relies on sorting everything out on a computer later, then even a couple of days of shooting is going to take you a while to process. As such, it's far better to get everything as close as possible in-camera and have minimal edits left for post-processing.
One of the ways in which you can minimize the amount of work you need to do in post-processing is to calibrate your camera. Many digital photographers are familiar with calibrating their computer monitor to help them get accurate results when adjusting images - some will even go to the trouble of calibrating their printers to get better, more predictable print results. But few think of calibrating their camera.
Whatever the device, the principle of calibration is the same. You create a custom profile for your device, so that color management capable software can make allowances for any variances. So when you calibrate a monitor, you're measuring how it varies from an agreed standard in how it displays colors. Top flight monitors might not vary all that much, but a lower-end screen might be significantly 'off'. The resulting profile is used to adjust how your images are displayed on that screen, to eliminate the discrepancy.
All cameras see colors differently and to recreate a scene as you remember it, you might have to make a number of edits in post-processing to render the colors accurately. Calibration will mean you have a better, more accurate starting point and so each image will, in theory need fewer edits.
Calibrating a camera works in a similar way: essentially you are measuring any variance in how it sees the world, and creating a profile to correct these individual differences at the Raw processing stage.
I first became convinced of camera profiling some years ago, when processing some images of an Irish sunset shot on a Nikon D2x. The colors came out too yellow and muted, and not the vibrant purples I remembered from the scene. So, on a whim I created a profile from a calibration image that I had photographed but never used, and then watched amazed as each image preview rendered in exactly the way I recalled.
Depending on your camera and light source however, you might not notice such a prominent color shift, but the theory of Marginal Gains teaches us that even apparently unnoticeable improvements in quality will add up.
Creating a custom profile for your camera has never been easier. I use the Xrite ColorChecker Passport and the plug-in that allows me to create profiles direct from Adobe Lightroom. You can also use the bundled software to create tailor-made camera profiles for Adobe Camera Raw. Adobe terms these as DNG profiles, but you don't need to convert your Raw files to DNGs (Adobe's Digital Negative format) to use them.
|ColorChecker Passport photographed in bright sunlight.|
The actual ColorChecker Passport consists of a standard 24-patch color target in a hard plastic case. You also get a grey card, which can be used for white balance and a color enhancement target, but the most useful is the standard color target.
Creating a camera profile
To create a camera profile, simply photograph the target under a given light. If you have more than one camera, then use each body, with the same lens if possible. I tend to use a mid-range zoom which is the one I use the most when out shooting. Since I'm capturing raw files exclusively and not JPEGs, it doesn't matter which color space - Adobe RGB or sRGB - I select in camera, but I always process the files in AdobeRGB since it gives a wider color gamut. You should use the same color space for both the calibration shot and subsequent images which will use the same profile.
The following is my workflow, using Adobe Photoshop Lightroom.
In Lightroom, select the imported image of the calibration target then select the Export command and then select the ColorChecker Passport preset that is loaded when you installed the software that comes with the Passport. Simply name your profile and the software does all of the rest.
After you restart Lightroom, the resulting profile can then be applied through the Profile pop-up in the Camera Calibration panel of Lightroom. Remember though that you'll only see profiles that are created by the camera that shot any Raw file you have selected. For an enhanced workflow, this profile can be saved as part of a Develop Preset and applied to a batch of applicable pictures.
|Adobe Lightroom Export dialog showing the ColorChecker Passport interface.|
The difficult thing is to work out how many calibrations you need to do. In theory you should perform a calibration for each lighting source, lens, and even ISO. In practice, unless you work in very controlled conditions this is probably too unwieldy and will slow up your workflow.
The trick is to find a balance for your type of shooting between having to create and apply so many different calibrations that it will be too time consuming and having too few profiles to be any use. As with most things to do with calibration, even having calibrated your camera once will be an improvement on most photographers' workflow.
How to use custom profiles
Working as a travel photographer, I tend to make a custom profile for each location area. So if I am shooting in the Himalayan region of Ladakh in India, I'll create a profile, and if on the same trip I were to head to a completely different area, such as the lush state of Kerala in the South of India, then I would repeat the process.
The ColorChecker Passport software has the ability to combine two different calibrations into a Dual-Illuminant DNG Profile. This gives a more accurate profile for your camera if you are shooting under any lighting source, and not just the sources you have actually profiled. What you'll need to do is shoot two different calibration shots under significantly different light sources. Then select the two calibration images and the software will create a combined camera profile, which is said to be much more accurate when applied under different lighting conditions than a single profile.
The sooner you perform these calibrations, then the sooner you can apply them automatically as a Develop Preset when importing any new images.
If you don't use Adobe Lightroom, then you can use the ColorChecker Passport standalone software to create your DNG Profiles, which can then be applied through some other Raw processing software including Adobe Camera Raw and CaptureOne. Currently, the ColorChecker Passport and DNG profiles are not compatible with Apple Aperture.
Steve Davey is a writer and photographer based in London. He juggles a young family with traveling as much as possible to some of the more exotic and photogenic parts of the world. Steve has just released the second edition of Footprint Travel Photography, which has been hailed as the leading guide to traveling with a camera.
The book is also available on Kindle, iBookstore, Barnes & Noble and Kobo editions. To complement the first edition of the book, Steve launched his own range of travel photography trips to some of the most photogenic parts of the world. Uniquely falling between a photography tour and a workshop, Steve accompanies each trip providing copious instruction as well as countless photo-opportunities. More detail on these trips and Footprint Travel Photography on www.bettertravelphotography.com.
Steve's professional site can be found on www.stevedavey.com