Graphics Programs Reference
In-Depth Information
The choice of a working space depends on the kinds of image editing you
expect to accomplish in Photoshop and where you ultimately intend to
output your files. Let's examine some of the RGB working spaces com-
monly used.
sRGB
This color space is an attempt at defining a RGB standard promoted by
HP and Microsoft. sRGB was intended for low-end devices such as con-
sumer digital cameras, scanners, and printers, as well as viewing images
on the Internet. sRGB was derived from HDTV standards and as such,
very detailed specifications of phosphors, gamma, and viewing conditions
define sRGB. It is questionable how many displays actually produce these
exacting specifications, at least without calibration. sRGB has the most
limited color gamut of Photoshop-installed RGB working spaces, however
sRGB does use a 2.2 gamma encoding.
Unless you wish to deal with only low-end output devices or output
images on the Internet, sRGB is not the best RGB working space for pro-
fessionals. This is due to sRGB missing a good deal of RGB gamut needed
for more sophisticated output needs including print work. If you have to
send an RGB document to an unsophisticated client who will view the
document on a PC outside of an ICC-aware application, sRGB is a good
option. sRGB is also a good color space to save images intended for the
World Wide Web since the vast majority of such users are working on
uncalibrated displays on a PC and as yet, so few Web browsers are ICC
savvy. See the sidebar, “The sRGB Debate.”
Apple RGB
This working space is based on the original Apple 13” Trinitron monitor.
Although its color gamut is not much larger than sRGB, those working
on a Macintosh using products such as Photoshop and Illustrator used
this as their working space in very early versions of both products. So
you see, some of us actually have been using an RGB working space all
along. The gamma encoding is 1.8 and unless you need to deal with files
from very old versions of Photoshop, this isn't a working space to
consider.
SMPTE-C and Pal/SECAM
These color spaces are both broadcast standards: one American, the other
European. If you're working with video, go for it, otherwise move on
to another RGB working space. These spaces are no longer installed
by Photoshop after version 5.0; but some might still be floating
around or installed on some users' systems. Don't say I didn't tell you
about them.
