Color Profiling Your Camera

Last updated on December 6, 2014

Color profiling your camera

Profiling your camera is one step in ensuring accurate and consistent colors.

The X-Rite ColorChecker Passport is available at Adorama, Amazon and B&H

Contents

  1. Introduction
  2. Profiling Defined
  3. Key Variables
  4. Creating a Profile
  5. Applying a Profile, Example One
  6. Applying a Profile, Example Two
  7. Conclusion

Introduction

Let's face it. Most folks go with however the manufacturer, either of the camera or the software, defines them. Just like cars, many go buy one and drive it happily until it is replaced. While others like to tinker, to customize things and extract better performance from them. Well, cameras are the same way. More specifically as it relates to color. Sure, your camera has white balance settings for daylight, cloudy, shade, tungsten, etc. These are optimal, lab-derived and factory-assigned defaults that typically give passable, average results - which are in reality, far from actually being optimal.

Is it worthwhile to pursue better performance from your camera in the form of more accurate colors? Is it worth the hassle of doing so? That's a big "depends." It depends on the individual and if they care enough about their photos to go after that last bit of tweaking. It depends on the intended use for the photo; will it be displayed online, in print or especially in a gallery? It depends on the audience; will it just be the photographer, their friends and family? What about the general public or worse, other photographers (who usually have a more critical eye for these things)?

Getting the "best" (in this case, defined as most accurate) colors from your camera doesn't need to be a hassle - but it does require some extra work. It is a small part of the bigger picture as it relates to color management. You'll (almost) surely want to also profile your display, so that what the camera records, what you see and eventually what you output, is all as expected and as it should be. If you print, you'll also want to profile your printer. This article will discuss color profiling your camera, with future articles addressing the other two aspects.

Profiling Defined

What is color profiling, how does it relate to a camera, and why would you bother? Color profiling allows you to, under various lighting conditions, ensure that the colors captured are produced by your post-processing software in the truest sense - consistently. Think of this as white balance (which in part it is) but also "mapping" what is recorded to what it should actually look like. You may have heard some say, "the sensor in this camera records hot reds" for example. What this means is that colors in the red spectrum are captured by the camera and show as excessively saturated... Even clipped (overexposed or "blown"). Color profiling will also help with this issue. You profile your camera so that the vivid blue sky you remember photographing, displays as the save vivid blue on your screen (or in print) - but also other people's screens, and be able to do this consistently.

There are three things that affect how color captured by your camera end up being displayed (setting aside printing for now). The first is white balance, or color temperature of the light that illuminates your subject matter. The "daylight" white balance is a very generic setting, found in every camera. It is generally standardized on a temperature of 6,500 Kelvin (K). The problem is, this is at high noon on a cloudless day. Sure, when it's cloudy you can switch to the "cloudy" white balance setting... But this too is very generic. Is it partly cloudy or is it really cloudy - even overcast? Same thing with "daylight." Is it early in the morning or late in the afternoon, where the light is more warmer and more orange/red (e.g. "golden hours") or is it more towards twilight, when the light is cooler and bluer (e.g. "blue hour").

The second thing affecting colors is the hardware - such as the sensor in your camera. Ideally, every sensor is neutral and records red (RGB 255,0,0) as just that. Or blue (RGB 0,0,255) as blue. In reality, this is not the case. Cameras typically adjust for this in their firmware, white balance settings and your post-processing software's profiles. But again, this is rather generic - variations in sensors can further skew results. The lens also plays a part in how colors end up. Lenses can impart a warming or cooling effect on colors; though in a perfect world, this shouldn't happen. An extreme example would be a vintage lens with a thorium (radioactive) lens element. They tend to turn yellowish as they age, and this will impart a noticeable warming effect.

Finally, there's the camera profile itself; a generic "best case" (in a lab) conversion of what colors are captured - and what they "should" be. The first step is internal to the camera, via the firmware. This cannot be (user) modified, and why the tweakers and purists among us like to post-process... What you can change is the way colors are represented through post-processing. This is where your custom camera profiles come into play. Though you need to shoot RAW/DNG rather than rely on out-of-camera JPEGs.

So in a nutshell, profiling your camera will ensure that regardless of light color temperature, regardless of sensor design or variation, lens or anything else for a given situation - will display colors as they truly should be. Any device, be it a screen or a printer, yours or someone else's - that is properly profiled - will also display the colors as they should be. While it's optional for the enthusiast, it's mandatory in commercial photography, especially for print.

Key Variables

So how much work will it be to profile your camera? That depends on the conditions under which you shoot, and how accurate your colors need to be. An easy case would be if you do product photography under studio strobes. There is little variation in such a case; namely the strobes. A (good) strobe will produce a fairly predictable color temperature, and this can be quantified and applied to your colors so that they are neutral and accurate (important in product shots). It gets a little harder for something such as "daylight." You can approach this one of two ways. The first to to create multiple "daylight" profiles; one for early morning/late afternoon ("golden"), one for high noon ("daylight") and one for sunrise/sunset ("twilight"). This will get you better colors than the default "daylight" profile while not getting to crazy about the ultimate color accuracy.

The second approach will ensure that your colors are accurate every time - but requires more work on your part. You do this by creating a profile for each shoot (or even shot). A shoot in this context would be defined as "a sequence of photos taken under similar lighting conditions in a moderate time frame." The opposite would be photos taken throughout the day, in varying light, and over a longer period of time. Color temperature changes not only based on the primary light source (e.g. quantity, quality and other factors) but also possible secondary light sources. Think of it this way; you want to lump the primary light source temperature close together so that you don't have to profile excessively (e.g. for nearly every shot). For example, you're going to the park at lunchtime to take some pictures of your family. The first frame would be of your color/profile target, the rest of your family. In post, you would create a profile based on that first frame which is then applied to each remaining photo (which can be done in bulk). This assumes you're taking pictures of everyone under that shady tree out back for the duration of the shoot.

The key variable for creating profiles is the color temperature of the primary light source in the scene. This will have the greatest impact on your colors. Applying that to our shoot example above, you'd want to profile for a sequence of shots under that shady tree - but another when you take pictures out in the sun - and another still when a rain cloud passes overhead. What this means is that you'll need to take a picture of your color/profile target each time the light changes for whatever reason. Though it's worth pointing out that if ultimate color accuracy is not your top goal, you can re-use profiles created under these conditions in the future.

Creating a Profile

The key to creating your camera profiles is one simple accessory. The color or profile "target." Simply stated, it's a small, simple device that has a variety of color patches and a greyscale that you take a picture of. They are typically accompanied with a piece of software that will then analyze this photo and create a profile for you - which is then used in your post-processing software/routine.

One of our favorite such targets is the X-Rite ColorChecker Passport. For about $60-100 USD you get a very nice target with accompanying software to generate your (DNG) profiles for applications like Adobe Photoshop (via Adobe Camera RAW) and Lightroom. The hardware aspect of it is a small, pocketable device that has not only 24 standard color patches for calibration, but a greyscale patch to check for clipping and additional rows of patches for warming/cooling the image consistently (as targets for your white balance). It also has grey card (also suitable for setting the white balance). It folds up for storage and transport - or opens up in a variety of configurations for ease of use in different shooting conditions. This device is what we'll be showing and using below. If you want to read more about it, check out the extensive user manual, brochure or this neat (third-party) technical report.

The first step is to take a picture of the target in your intended lighting. We chose to shoot the target under studio strobes to start with, to illustrate the easiest scenario and especially the workflow. Many cameras these days output DNG files, and Leica M cameras are no exception. But in case it doesn't, use something like Adobe's DNG Converter to get the job done, as it's the only format the software from X-Rite for the ColorChecker Passport understands. This is logical, since it only creates DNG (not ICC) profiles. When creating profiles and taking your first shot, make sure the target is shot at a decent size (at least 10% of the image), ensuring that it's evenly lit and that the exposure is good. No sense starting off with uneven lighting and clipped channels, though the software will warn you about the latter and refuse to create a profile. It should also be in focus and relatively parallel to the camera sensor to lessen distortions. It's smartly designed to stand on its own in various configurations and comes with a lanyard to hang around a subject's neck (or tree branch, for that matter). With the DNG on-hand, drop it onto the app:

In most cases, even if the target is rotated, the software will automatically locate the patches and set up sample boxes appropriately. If you're happy with what you see, click "Create Profile." In the resulting dialog box, you can change the name - it defaults to just the camera model (automatically identified). It's a good practice to add some identification as to the lighting involved, for example "studio," "shade" or "overcast." This way you can identify them easily later. From here, you can either create more - or move on to post-processing your images. It's that easy! Now we're going to look at two cases of applying this profile.

If you're just using the target to set consistent general white balance, exposure or warming/cooling tweaks - it can be located pretty much anywhere in the frame, rotated, whatever - as long as the light falling on it is the same as your subject and you're able to see it. You can then easily click on various patches with the dropper tool to do what you need. This is how it's most often used, actually. For example, you're going to take someone's portrait under a tree. Have your subject hold the ColorChecker Passport and shoot a frame. For the following actual shots, just take it away. Then in post, you can grab your values from the first shot - and apply it to the other(s). Easy as pie!

Note that the colors in the following examples will depend on several things. Is your browser color managed? Most current ones are. Is your display decent? Desktop monitors generally (but not always) are, but laptops generally lag behind. Is your display profiled? If you're a photographer, there's a good chance - though many people might just have whatever default was assigned, be it a generic monitor profile or simply sRGB. The following images are all 8-bit JPEGs, but are using and tagged with the ProPhoto RGB profile. So you should see what we're talking about...

Applying a Profile, Example One

Let's take an easy example; the aforementioned studio strobes. We're going to take a picture of the target under excellent lighting conditions and just focus on that, so we can look at the workflow first. Using strong, professional strobes that output clean white light - it's easy for most cameras to get the white balance pretty close when set to automatic. So we'll go with that on the first couple of versions below.


Adobe Standard profile


The target as opened up in Adobe Photoshop, with the basic "Adobe Standard" profile applied. This profile is available regardless of camera used to take the picture. It does an "okay" job, but it's nothing special - and in most all cases, does not accurately reflect what your camera (generally as a brand, the model or specifically yours) has captured. We'll use it as a baseline however. The white balance is actually pretty good, and was determined by the camera ("As shot" in ACR). A shortcut, no doubt. We could have just as easily chosen any of the other canned white balance presets.


Camera profile applied


Now we're getting closer to what the colors should look like, by selecting the standard profile for your camera model as provided by Adobe. Better than the generic "Adobe Standard" but it's not specific to your camera, which will likely differ slightly for various reasons. Don't confuse this profile with several that may be available; so-called "film simulations" as they apply a particular, non-neutral "look" to the image. Again, the white balance is pretty good, and was determined by the camera as above.


Custom profile applied


Now we're really getting somewhere. The profile applied is specifically for your camera and lens now, which we created earlier. One last time, the white balance was determined by the camera and not bad at all.


White balance adjusted


By using the white balance tool on the appropriate neutral patch, that is - one that does not warm/cool the image - we finally take into account the color temperature of the lighting as accurately as possible. There's no guessing as to how the camera arrived at the white balance it did (which can be quite far off) and is similarly much more accurate than the canned presets (which are "best case" scenarios). The fact that the image didn't really change much over the previous version indicates just how close the camera got to getting it right! Colors are now about as accurate as they can be, but we still want to tweak the image just a little bit more...


Levels adjusted


Sometimes we want to ensure that the whitest white is "white" and the blackest black is "black" - which will make everything in between fall into place. To sort of "snug up the ends of the histogram" as it were. Ensuring that white is actually RGB 255,255,255 and black is actually RGB 0,0,0 - is accomplished by utilizing the greyscale clipping patches on the target and the clipping indicators in Adobe Camera RAW (ACR). The sliders for whites/blacks are tweaked as necessary so that they're at their maximum before clipping occurs. Rather than through ACR, you can also use Photoshop's "levels" or "curves" dialogs, or the curve tool in the Exposure panel (under the "Develop" module) in Lightroom.

You should now have a fully color corrected and tweaked image! Be careful though; this can dramatically affect the contrast of your image and not always what you want. Which is why we said "sometimes" - as sometimes you might want to leave things as they are, or simply eyeball it. So do whatever suits your taste on this step.

Applying a Profile, Example Two

In this second example, we're going to use a more common, "real world" scene. Given the time of year, how about a Christmas tree in mixed light? The primary light is from a dark, overcast sky - with secondary lighting consisting of mixed tungsten and fluorescent. Pretty rough conditions to get accurate color without profiling. As before, the camera's automatic white balance was used in the first three shots, before being set accurately in the final photo. So let's get started - first by creating a fresh profile for this funky light...

We wanted to push the ColorChecker Passport profile software a little bit and shot the target not only upside down, but also slightly out of focus. The software did have issue automatically acquiring the target. No worries - we simply located the corner marks on the target manually (four clicks) after which the color swatches were then automatically located and we created our profile. Simple, easy and fast.


Adobe Standard profile


As before, we started off with the "Adobe Standard" profile as a baseline - and white balance was automatically determined by the camera. Notice that the reds are somewhat muted, the greens dark and kind of "blah" but especially the areas that should be white - under the mixed lighting. Our eyes do a good job of just making it all look right, but cameras are not so forgiving.


Camera profile applied


Next up, we applied the Adobe-supplied profile for the camera model, and again, the white balance was determined by the camera. The reds and greens are looking a bit better, but still kind of lifeless. The whites in the image aren't much improved.


Custom profile applied


This is where it gets interesting, as we have applied our new, custom profile to the image. This is the last shot where the white balance was still set to auto. Notice the reds and greens in the photo, and the white areas such as the floor and back walls (which are slightly warm) and the walls higher up, towards the windows (which are slightly cool). Now you can see why this is a good torture test for accurate color.


White balance adjusted


In this last photo, with the custom profile applied - we set the white balance to what our ColorChecker Passport provides us (as determined by where it was held - in this case, the light falling directly on the tree). You'll notice the reds now pop a bit more, even the greens. The floor is looking better now, and the lower walls lit by tungsten lights appear more realistic. The upper walls are more neutral (white) looking also. This is the accurate representation of the scene! Now scroll up and look at some of the other photos again and look for the differences, which should be fairly obvious where it's really off or, to make it easier - compare them side by side:

Conclusion

So this is color profiling your camera (and by extension, your photos). Just how far you want to take it depends on your goals and to some extent, your patience. If you want the most accurate colors possible... Sure, it's a bit of work. But with practice this takes only a little extra time. In the end, you'll probably find it's worth it - at least for tricky lighting situations. Plus, you'll guarantee that not only you see the colors the way they should be - but others as well.

If you're interested in getting your own X-Rite ColorChecker Passport, and we highly recommend one - it is available at Adorama, Amazon and B&H. Check each one for the best price, as they're often discounted - we had a heads-up here a while back where it was available for only $59 USD! At the time of this writing, Adorama has the best price at $89 USD.

To get the most out of this exercise and ensure more accuracy, not just in how you (and others) see the colors of your photos - but how you intend them to look - is to ensure your monitor is also profiled. We'll take a look at this other critical step in an upcoming article.