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| MORE IS BETTER: Color accuracy is an important indicator of image quality. But color saturation and gamut also contribute, as evidenced by this flower shot. The top portion has low color saturation and a narrow gamut. |
How many colors can your digital camera capture -- thousands, millions, billions? Can your computer display them all? Your printer reproduce them?
You can't tell from spec sheets, where the only mention of color is usually an obscure "8–14 bits/color (RGB), or 24–36 bits total."
Understanding how many colors your camera, scanner, monitor, projector, or printer can reproduce -- and how these devices communicate color to each other -- requires an understanding of color gamut.
Sure, you can turn your camera and printer back to their default settings, and let someone at a photo lab figure out how to get the "right" color from your images. But if you want to control their look from capture to output -- or to buy a new camera, scanner, monitor, or printer based on its color capabilities -- then knowing the basics of color gamut will help. Want to be a pro photographer or master printer? An advanced understanding is essential.
The concept is easy: Imagine a crayon box in several different sizes, ranging from a small box of 10 different crayons to a huge box of 16.7 million different-colored crayons. Okay, that one would be the size of a warehouse, but 16.7 million is roughly the number of shades in a 24-bit color image.
Give a talented artist all the time needed to reproduce a real-world scene using 16.7 million crayons, and the drawing might approach photo quality. (Obviously, a 10-crayon drawing would look worse than a 16.7-million-crayon one.) The ability of the artist (or imaging device) to choose the right hue to match an actual one in the scene can be defined as color accuracy, while the number of different crayons (or colors) to choose from is the color gamut.
Most digital cameras can capture at least 16.7 million colors depending on the lighting, while some DSLRs can recognize even more. Other imaging devices, such as LCD monitors, have progressively smaller "crayon boxes."
On the other hand, the color gamut of most cameras will vary based not just on lighting conditions and the camera's color space (the large-gamut Adobe RGB or smaller sRGB) but on image settings such as contrast, saturation, and white balance.
A monitor's color gamut might vary based on its calibration, contrast, and brightness settings. And a printer's color gamut could vary based on the paper and ink, driver settings, and even the relative humidity of the room.
Because of all these variables, we concentrate on the color accuracy of these devices in our product tests and reviews -- and try to standardize the lighting conditions, calibration, and types of papers used in those tests.
In our printer tests, we describe the size of the color gamut (using premium photo paper), so you get a better idea of how many "crayons" it can mimic. We also generate three-dimensional color gamut graphs using information from color profiles, which we create in the Pop Photo Lab during testing.
The size and volume of a printer's color gamut cloud represent the relative size of its "crayon box." The cloud shape tells you more about its strengths and weaknesses: Highly saturated colors are on the outside of the graph, and less-saturated hues are closer to the L axis. Grayscale values run along the L axis.
In the end, though, all you really need to know is that the larger the color gamut, the better. And, fortunately, it doesn't take a big warehouse to store all those colors or a fortune to buy them.
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