Color Management Systems
For many serious photographers, the idea of color management systems is a confusing and frustrating subject. Once again, it all arises from the fact that YOU are now totally responsible of all aspects of your photography – from capturing the shot to “developing” to the final print.
In the pre-digital days, there were a few well understood choices for a lab – the paper’s properties were well known and well understood; likewise the chemicals and their effects were consistent and proven.
But all this has changed with digital photography. (And for me it’s the perfect situation. While I did spend hours in a darkroom, making prints, it was the least satisfying part of the process. My problem is “attention management” or excuse the pun, “a short focal length” – can’t keep on one task more than a few minutes – there’s soooo much to do, why devote scarce time to just one thing. Hey, I’m the poster child for multi-tasking!!! But this mindset doesn’t work well in the darkroom, so I’m happy to leave it all behind.) So HOW can these changes work to your advantage in the digital world.
YOU are in control 100%. You can make the image exactly the way you want it. From a creative perspective nothing is better!
And to make the promise of digital work and work well in this regard, you have to learn about color management systems. Even if you are not attention-challenged like me, your images will just be better. And if you didn’t read the SIMPLE Method pages, I’ll say it again here. The print IS everything. It’s what people buy; it’s what you show; it is the art and soul of a photograph. So why spend hours composing, waiting for the right light, thinking, analyzing, even manipulating your image in the computer, and then NOT make the best print you can?
“Shoot for show, print for dough!”
What are Color Management Systems?
Color management systems are designed to overcome the problem of inconsistent color interpretation between devices. They really do only a couple of things: they describe the color of pixels, and they change the values of pixels to keep the color consistent across these different devices. If you’ve ever pulled you hair out wondering “why does my image look great on my monitor and horrible when I print it” or if your image looks like a disaster on your monitor but looked great in your camera, you’ve experienced a color management system. A broken one for sure, but it is color management just the same.To understand how color management systems can fix this, let’s look at why there’s a difference in the first place.
Computers aren’t color machines. They are number machines. That’s why we give numerical values to colors. Either RGB values, hex codes for the Web, and even for CMYK color is commercial printing. You’ve seen these before – in your color palette in Photoshop for example, RGB red is 122, 10, 10 or #F20A0A or 0,100,100,0 in CMYK. All numbers, to tell devices how to display a precise color.And it works great. Every time you type 122,10,10 into your color palette in Photoshop you WILL get the exact same color. But as we all know, that all changes when you print your image.
And this happens because of the differences in the way your monitor creates color and the way your printer does. Your monitor uses light (RGB) and your printer uses ink (a combination of CMYK inks). “But what about my scanner?” you ask. “Why does it not reproduce the same as my monitor?” Well, each manufacturer and each device has a slightly different way of interpreting the electronic signals generated to create the colors; and the optical capture technology varies from device to device as well. So your color shifts from device to device for all these reasons. RGB and CMYK are device-specific or device-dependent color models, because they can only produce predictable results on a given device – often called ambiguous color. This is the big problem that color management systems seek to address. The second, more-obvious problem stems from the first: how to solve the color changes when we send our files from one device to another, or unstable colorIf you want a far more technical explanation, I’ve included some good links at the bottom of this page.
How Color Management Systems Work
Color management systems try to solve both the problems of ambiguous color and unstable color — using three components:
- A reference color space that represents color as we see it. (This is simply another type of color model – like RGB and CMKY) See this color management systems article for more details about these.
- Device profiles, which describe a device’s color behaviour (all those interpretation of signals etc).
- A color engine, which is a piece of software that does the actual work of matching color from device to device.
Each of these components helps keep colors consistent across devices. Sounds great right!?
Color expert Bruce Fraser explains: Most color-management systems use two reference color spaces, called as CIE XYZ (1931) and CIE LAB (1976). You can find a more detailed explanation of the basis of CIE XYZ (and its later derivative, CIE LAB) in Out of Gamut: Why is Color? But forget all the tech stuff for now, just know that 1)LAB is a straightforward mathematical equivalent of XYZ2) Both XYZ and LAB represent color in terms of human perception, rather than in terms of the control signals we use to make a given device produce color. In other words, both color spaces let us specify the color a human with normal vision can see. As a result, XYZ and LAB values define color unambiguously, unlike device-dependent color models such as RGB and CMYK.
A full library of color management documents is available for free at the ICC There’s an excellent one concerning digital photography too.
Device profiles are descriptions of how all our various devices when they reference a color. They translate the RGB or CMYK values into LAB or XYZ values taking into account, the way the device interprets color. And vice versa. Printers have their own profiles, and you can also get third party profiles for various printer models. The ones that come with the printer are generally generic and not that great for precise color requirements. For example between the various models of Canon printers, each render color in a little bit of a different way. But the profile that’s included with the printer will likely be a generic Canon printer profile. It usually better to buy a specific profile or to create your own. More about Creating Printer and Device Profiles here.
The color engine is the active part of color management systems. It is software that changes the color value numbers in our files as we go from device to device, with the goal of keeping the color consistent. This software is the “guts” of the color management system and ensures that all pieces are communicating; in addition it reconciles the color value, applies the profile data and produces a consistent color result It adds a little here, takes away a little there to render your color exactly (or as close as possible) as you saw it.
Interesting – But how the heck do I USE all this to make my prints better!?
Great question, here are the steps. The links will take you to the details page.
1) Calibrate your Monitor (advanced)
2) Create or install printer profiles (advanced)
3) Configure Photoshop (for everyone)
4) Set up your camera
Color Management Systems Resources
Norman Koren’s deeply technical about Color Management Systems