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Color Management: What You See Is What You Get
The Significance Of Color Management For Photographers
 Undoubtedly, the proliferation of digital imaging is thrilling news for shutterbugs. But it magnifies a point of concern – the consistency of color. Professional/amateur photographers and beginners often find that the image color is hardly unified through the workflow from viewing, editing to output. In particular, the color of the same image may appear differently on different screens. To make unified image color possible is the fundamental requirement of users and the ultimate aim of color management. This column, courtesy of Datacolor, is a series that examines common problems that users often find in their digital workflow.
In our past two issues, we have given examples of two individuals who, though each have different workflow and characteristics, face problems that are color-related. It all boils down to one main concern – the way to measure print colors accurately.
Human eyes perceive numerous colors everyday. In fact, hundreds of colors flash across our minds each second. Apart from objective factors, different individuals have their own subjective preferences, which makes it impossible to calibrate colors by human eyes. Therefore, photographers cannot and should not measure their photographic works based on what their naked eyes see or by experience. To illustrate, let us first understand how colors are perceived.
Deconstructing Colors – Different Colors on Different Cameras
The world we live in is a beautiful place, filled with colors. But for colors to exist, three basic elements are necessary: light, object and the viewer.
The white light that we see is made up of red, blue and green light waves in varying intensities. When light waves strike an object, the object absorbs some of the light waves while reflecting the rest to the viewer – that’s how we see colors. In other words, we see green grassland on a sunny day because when the sunlight falls on the grass, the red and blue light waves are absorbed while the green light wave is reflected to our eyes. The more red and blue waves are absorbed, the greener the grass will look.
We know that when all three light waves are being reflected, the resulting color we see is white. But does a composition of red, blue and green light waves really produce pure white? When the light is reflected into our eyes, our brain will modify the color to “deceive”us so that we see “white” as we know it and not as it really is in reality, for example, with a tinge of green. How then can we rely on our eyes to judge colors accurately?
Adobe RGB vs. sRGB
For this reason, we have today fully developed color management systems. Particularly for processing color images, the industry has defined various color models, which we will learn more about first, before moving on to the topic of color management in our next issue.
A color space represents the range of colors that a color image contains. RGB (an abbreviation for Red, Green and Blue) is one of the many different color models and includes Adobe RGB, sRGB, Apple RGB and ColorMatch RGB. We will focus on the first two, which are more commonly used. Both developed by different manufacturers, Adobe RGB has a broader color space than sRGB and thus is able to produce more color details. For example, if the color space of an image is changed from its original Adobe RGB to sRGB, some colors will be lost although the remainder will still be sufficient to reproduce the image vividly.
On the other hand, if the color space is changed from sRGB to Adobe RGB, you may notice some slight color changes in the image but only because these “additional” colors are simulated by the output device (i.e. your computer). In reality, these “additional” colors cannot be produced because sRGB contains fewer colors than Adobe RGB and there are simply no extra colors available to fill the gap created when you “enlarged” the color space.
A Non-Standard “Standard Color Space”
sRGB, which stands for Standard RGB, is today the default standard color space in most hardware and software and even consumer digital cameras and therefore, it is theoretically possible for images from digital cameras to be displayed on monitors and printers right away without any need for further processing.
However, in reality, colors vary across cameras. Two cameras that are calibrated with the same settings (aperture, shutter speed, white balance and sRGB color space) can still reproduce colors differently because sRGB is defined by the industry as a referential color standard only. In actual practice the results may vary according to the structure and sensor of each camera. Since sRGB is only a general standard, different cameras that employ the same sRGB color space can still interpret colors differently, depending on the structure and sensor of each camera.
Digital SLR & Prosumer Digital Cameras
Apart from sRGB, most prosumer digital cameras or digital SLR cameras offer other color space options as well and Adobe RGB is most commonly used. With a wider color range than sRGB, Adobe RGB enables more color details, although each camera’s structure and sensor still affects its color performance.
The same applies for computer monitors: different monitors represent colors differently and even if they are all using Adobe RGB, they still need to be calibrated to get consistent performance. Just as there is a color standard for digital cameras, so is there for output devices. Typically, computer monitors are built with sRGB as the default color space, but many users choose to use Adobe RGB instead because of its ability to better reproduce colors and details than sRGB.
When we shoot in JPEG format, it is necessary to choose an appropriate color space, but what about shooting in RAW format? There are many benefits of shooting in RAW format, but more importantly, RAW files allow greater flexibility in color control when it comes to color management and makes it easier to edit images since it retains more image information. When converting an image from RAW to JPEG, we can even choose what color space the latter will use.
This column is brought to you by: <<please insert Datacolor logo, which was given to you previously>>
About Datacolor
Datacolor technology provides affordable, easy-to-use digital color control products to creative professionals, photographers, corporate customers and consumers around the world. Because color matters, leading businesses, creative professionals and consumers worldwide choose Datacolor’s innovative technology solutions to consistently achieve the right color.
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