A New Level of Color Quality Control
We have exposure and focus control built into the camera. If needed, we can fine-tune exposure in the raw converter. With digital imaging, contrast control is a piece of cake. We can manually control depth of field simply by presetting a desirable aperture. We can control perspective with zoom lenses and our legs. White balance is readily taken care of by the camera and can easily be fine-tuned in the raw converter. But what about color accuracy control? Not to mention color accuracy in artificial light like fluorescent and LED?
Profiling the camera
Let's compare a number of different cameras. Matching exposure, contrast, focus, DOF, perspective and grayscale balance are not difficult tasks, even for less experienced photographers. But when it comes to matching colors, especially in difficult light, it's a completely different story. While exposure, contrast, etc adjustments are pretty much straight-forward or "linear" and easy to implement, exact color is much more complex.
The method for accurate color adjustment is called profiling and is found in the color management discipline. A profile is created in a dedicated application. The first step is to compare camera acquired color values with desired color values and determine color deviation. Next step is to create a conversion table that changes color values in the opposite direction. If the comparison step tells us that a photographed red color with a certain lab value comes out with a different lab value when camera X is used, the custom profile for this camera will reverse the acquired red tone to resemble the desired red tone.
A color managed workflow
Color management is a digital image product. It is used to equalize color description when colors are transferred between different devices like a scanner, a monitor, a printer, a printing press and a camera. We take a picture with our camera. The picture is transferred to the computer memory. Then it is viewed on the monitor and printed on the inkjet printer. In a perfect world, colors from the photographed scene match the colors on the monitor and the colors on the inkjet print.
In order to achieve a "perfect world" picture environment we can choose two directions.
The "quick and dirty" way is to create a closed-loop environment. Take a picture with your camera. Print the picture. Adjust the monitor until it matches the colors of the print. It's simple. It works. But it has several limitations. You are not taking advantage of your devices full color potential. Colors will be perceived differently as soon as the pictures leave your environment.
The recommended way is to color manage all devices separately. Use a software to analyze the color interpretation and to create a correction table (profile) for each device. You will have a profile for your camera activated when you develop your pictures in the raw converter. You will have a monitor profile and a printer profile activated in your system, in order to guarantee highest possible color perception fidelity. When you send pictures to friends or a client with a color managed system, they will perceive your pictures the same way you do.
Important: white balanced eyes
One more thing - our eyes. Human eyes are amazing. Human eyes can white balance instantaneously and locally. This ability, as impressive as it is, can also jeopardize our color judgement. In order to correctly perceive colors on the monitor, your eyes must be "white balanced". Color temperature of the ambient light must match the color temperature of the monitor. Furthermore the environment surrounding the monitor and the monitor desktop must be neutral. Gray color on walls and desktop and no yellow Post-it notes, prevents your eyes from un-matched color balance adaption.
In order to accurately perceive colors in digital images, standardize (color manage) all your devices, including your eyes.