Graphics Programs Reference
In-Depth Information
a 1.8 gamma encoding. This working space gamut is so large that a
portion of the plot of its gamut falls outside the CIE chromaticity diagram.
Nonetheless, for a huge gamut space, it is well behaved and many users
have found success bringing in high-bit (more than 8-bits per channel)
from wide gamut capture devices such as high-end digital cameras. If you
happen to be a person who works with such a device, or you want to
ensure that you have a working space for your files that is very large for
archive purposes, ProPhoto RGB might be a better option than using
Wide Gamut RGB. I've found ProPhoto RGB to be an excellent working
space to use when converting RAW digital camera files using Adobe
Camera RAW, which is discussed in Chapter 5.
Sidebar
The sRGB Debate:
Much has been written about sRGB and a lot of it not very positive. Some
have called sRGB “Satanic RGB,” and others have used the “s” to describe a four-letter word
even worse (and unprintable). The sRGB space has a role but it has been overplayed by a large
number of mostly consumer manufacturers. What's the story here? sRGB does have the small-
est color gamut of any of the standardized RGB working spaces installed by Adobe Photoshop.
In a world where “more is better,” we have to wonder if this is the reason the space has received
such a bad rap. Could it be due to sRGB being designed and to a large degree pushed by
Microsoft?
There's no question that for most Photoshop users, sRGB probably isn't the best option
to work with. For one, its gamut is rather small and even the typical CMYK print/output space
has a larger color gamut. Many digital cameras and some scanners default to encode data in
sRGB. The initial color data almost always has a greater gamut. sRGB has become the poster
child for manufacturers who want to dumb-down color management while producing an RGB
document whose numbers have some meaning. This isn't necessarily a bad idea assuming you
understand the limitations. Is the meaning really accurate or correct? For printers that we are
told “produce sRGB,” I can say this is not an accurate statement. The only valid sRGB “proof-
ing” device is an sRGB display, as this is what the sRGB color space specifications are based
upon.
Digital cameras that allow the user to funnel images in sRGB are encoding the original
data based upon what the manufacturer feels will produce acceptable color viewed on a display
that is producing sRGB. In theory, if someone views this data on a display system (uncalibrated
and outside an ICC-aware application) that closely behaves like that of an sRGB display, the
image will preview accurately. I have to question the logic of shooting into such a small gamut
color space when clearly there are output devices that can utilize a wider gamut of colors for
printing. Funneling color into such a small space is a practice that paints many users into a
corner.
If you need sRGB for some reason, such as placing images on a web page where this color
space is really most appropriate, there's no reason a wider gamut capture and editing space
can't be used. Then that wider gamut space can be converted to sRGB for that one use. Once
a document is converted into sRGB, there's no going back to a larger space. The original color
from the wider gamut space is clipped to sRGB and gone forever. So, keep your options open!
