Color Management

How colors are interpreted and shown in the present day work-flow is a matter of confusion for most. When I was trying to explain to a friend about color management, I was faced with the problem of how to get the whole thing down to easily understandable terms. Color management and color space are the backbone of color photography.

 

Color Space

There is a total range of colors that a camera can capture or a monitor can show. There are limits to how many colors these devices can work with. This is called as the gamut of colors that the device is capable of handling.

 

(Colors in a horse shoe shaped graph. These are all the colors that are visible to human eye)

 

To understand the color-spaces, the easiest method is to represent the colors on a graph. Conventionally an almost horse shoe graph is used to represent the range of colors. The center of the graph is without any distinct color and as we go towards the periphery of the graph, the colors start to appear. Further out towards the periphery, the more saturated the colors are. The ends of the graphs are red, blue and green. This is the whole range of colors that are possible. All the devices have their range limited within this range of possible colors. The range of colors any device is capable of working with is represented by another outline within this colored graph (which roughly looks like a triangle) and this is termed as the color gamut which the device is capable of handling.

Each of the colors that are there in a photograph are made up of a mixture of red, green and blue (RGB) hues. The saturation of each of these hues represents the final color. Each of these red, green and blue are given a value from 0 to 255 (on a 8 bit depth). So a red of value of 200 will be more saturated than a red of value 100. For producing purple, a mixture of red and blue are required. An example of purple color represented in RGB values can be 200,0,200. Here red has a value of 200, green has a value of 0 and blue has a value of 200 again. Similarly different tints and shades can be created for a big range of colors by varying the RGB values.

Now comes another question. How do we ascertain that the red with value 200 will look the same across all displays? For this to happen, the range needs to be defined. The values from 0 to 255 have to correspond to a specific saturation of the color. This is the color space. The 255 value will represent the most saturated color available in that color space.

sRGB is the most common color-space that is presently compatible with each and every electronic device that has anything to do with photographs. Adobe RGB is the next big thing that came to the photography. This is a slightly larger color space with capabilities of handling more extremes of saturation. Most dedicated photography electronics are now capable of working with AdobeRGB too. It is a better color-space than sRGB but not so widely compatible with various devices. There are some more color-spaces which are even more defined than Adobe but these are quite uncommon – eciRGB, scRGB, ProPhoto RGB, ColorMatch RGB etc. If you are reading this article, my suggestion is to stick with sRGB or Adobe RGB if you know for sure that all your equipment is compatible and you do not intend to share the digital photographs with anyone else. Forget about the other color spaces.

 

Colorspaces

(Some common color spaces represented on top of colors that can be seen)

 

Color Space and Gamut

Now that we know that the range of colors that an electronic device can handle is called gamut and we have also understood the representation of the range of colors from the lightest to the most saturated is called the color space, we can proceed one step further in what works in the real world.

The color space that can be used with a device is limited by its color gamut. Is that not logical? If I were to choose a really really deep saturated blue color to show on an inexpensive monitor that can not handle it, how will the monitor be able to show it? There’s no magic in there. So to limit how the colors can be shown by the monitor, the photographs use the information from the color space and work within the gamut of the device.

With the advancement in technology, the gamut of colors that devices are capable of, has increased quite a lot. Larger color spaces can now be used. Keeping everything in sync is the reason why color management becomes important.

 

Color Management Basics

Get a good monitor. I recommend a decent IPS monitor. On my desktop, I have an inexpensive Dell IPS monitor. High end monitors from Dell, Apple, NEC, Eizo and a few other companies are nice but a little expensive. Lately I have been told that Barco, the medical displays’ company, also manufactures some good monitors which can be used for photography. 

I personally prefer matte finish monitors since they don’t show my reflection in the dark photographs.

Create a good work environment. The light around the computer should be sufficient and preferably of the same color and amount which you plan to work with on a regular basis. Consistency is the key word here. I always love to work on my computer in day time when the diffused day light streams into my room through the frosted glass of my window panes. For evaluating the prints, I have a bright table lamp with a bulb which matches the color temperature of the ambient light. It was quite an expensive bulb. Thankfully my wife still doesn’t know about its cost. My room itself is painted in white, which avoids any color casts and reflects good amount of ambient light.

Desktop wallpaper – Set it to something in grey. I use a simple mid grey tone (close to 18% grey) as my desktop wallpaper. This prevents my eyes from adapting to any specific color. The longer our eyes stare at a color, the less sensitive they become to it. So it is better to avoid colorful wallpapers on your computer. Now do you also understand why all the popular photo-editing applications have a grey background?

Calibrate the monitor. This is even more important than getting a good monitor. I use a Spyder colorimeter and software to calibrate and fine tune my monitor. There are various online options also available that can be used to calibrate monitor to acceptable levels. Here are three good options (links open in new tabs)

  1. http://www.w4zt.com/screen/
  2. https://www.drycreekphoto.com
  3. http://www.lagom.nl/lcd-test/

Check the color space in your camera if you are clicking jpg and ensure that it matches that of your monitor. If you are clicking raw, skip this step.

Post-processing and image editing programs also seem to have a mind of their own. Sometimes the color space these work in can be set at something different from the one being used by the operating system by default. Go and dig into the settings of your loved programs and ensure that the color space is set correctly.

Print is the final culmination of photographic endeavor and it is the best way to display your masterpieces. The simplest way for most people is to use the services of a neighborhood photo-printing store or an online photo-printing company. If you want everything in your control, then get a good photography printer. Next step is to obviously calibrate the printer to actually print the photographs closest to what is visible on your monitor. Let the printer manage the color space. The simple way is to print some example photographs and then carefully tweak the printer settings. A more idealistic way is to use a printer calibration solution which is commercially available. I have tweaked my printer settings by printing example photographs and manually adjusting every value.

 

Boats on Ganges

(Boats on river Ganges – Nikon Df with Zeiss 25mm lens, f/8, 1/160 sec at 100 ISO. Good color management is required even for working with black and white photographs)

 

A word of advice – write down the printer settings and keep it safe. Reinstalling operating system, printer software and sometimes even upgrading the installed drivers can wipe out the settings. Instead of going through the struggle (not to mention the cost of wasted paper and ink) of printing and matching colors from prints to monitor, these noted down settings can save the day.

 

Chromaticity Diagram – by Paulschou / Wikimedia Commons / CC BY-SA 3.0
Color Space Diagram – by Cpesacreta / Wikimedia Commons / CC BY 2.5

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