Graphics Programs Reference
In-Depth Information
See Chapter 9, Tutorial #11: “Using Photoshop to Build Simplified
Camera Profiles.”
Adobe Camera RAW and Color Management
As the geek wars over creating digital camera profiles raged on, another
major disagreement broke out surrounding Adobe's RAW converter,
which first appeared in Photoshop 7.0. This product has no provisions for
installing or using custom ICC camera profiles. Several color geeks, myself
included, found that not only was this not a hindrance, it was a benefit!
This sent some shockwaves through the color geek community. How
could a number of well-known color experts consider a tool that didn't
use ICC profiles?
Truth be told, the product does use two input profiles built by Thomas
Knoll, the father of Photoshop. Although not ICC profiles, Thomas was
able to produce spectral data from two light sources for each camera: Illu-
minate A (tungsten) and D65 (daylight), which are both used to adjust
the white balance of the RAW data upon conversions into RGB. This
Photoshop plug-in extrapolates between the two profiles based on how
the
Temperature
and
Tint
sliders are manipulated (see Fig. 5-10). These
controls are adjusted visually, on a calibrated display, until the image
appearance satisfies the user. The
Hue & Saturation
sliders in the
Calibrate
tab modify the profiles in order to fine-tune the effect and to account for
differences in camera model variations. These sliders allow the red, green,
and blue hue and saturation to be tweaked while leaving neutrals
untouched. This operates like a profile editor but in an easy-to-use
fashion. Once adjusted, these settings usually can be left alone or saved
and loaded for use at any time.
The big advantage of
Adobe Camera RAW
is that input profiles are not
necessary as far as the user is concerned. The color appearance seen in
Adobe Camera RAW
matches the color appearance after a conversion into
the desired RGB working space. The numbers provided in the
Adobe
Camera RAW
's info palette are the numbers that will be seen after a con-
version from the RAW data into the desired RGB working space. We have
WYSIWYG and the results are images rendered and encoded into one of
four well-behaved RGB working spaces.
There isn't anything unique about how
Adobe Camera RAW
operates
that doesn't fully conform to good color management practices and the
imaging Pipeline. The product does expect the user to produce a desired
color appearance using the numerous tools provided. This isn't any dif-
ferent from opening a color managed document in Photoshop and alter-
ing its color appearance using accurate previews and accurate numeric
feedback. The product does handle the RAW data as if it were a color
negative, whereby conversion for the RAW Grayscale data into a color
managed document is up to the user to interpret. Some users have com-
plained that the default settings in
Adobe Camera RAW
do not produce the
