Graphics Programs Reference
In-Depth Information
ing the
Photo Task Options
button, a number of tabs become available to
control how the camera profile is built. Options available allow an auto-
matic gray balance to be used on the target data or instead, an option to
use the gray balance produced when shooting the target. Other alter-
ations allow exposure compensation and saturation tweaks to be made
to the resulting profile. One interesting and quite useful feature is found
in the
Spot Colors
pane. It is designed for those shooting demanding or
difficult colors of objects in a studio situation. Here a user can hook up
an Eye-One Pro Spectrophotometer to measure actual color from objects
to be photographed. The resulting profile will compensate and skew the
camera profile in favor of these specific spot colors. Therefore, if a pho-
tographer were shooting an oil painting and certain colors of pigments
were causing problems, such as metamerism, the photographer could
measure those colors directly from the original painting and the profile
would attempt to handle these important spot colors with added accu-
racy. This is functionally akin to making a custom camera target, except
this is done inside the profile generating software. All the options seen
in Fig. 5-9 can be saved as a document and reloaded in the future to gen-
erate a new set of profiles. With all this control comes more work in so
much as a user may spend a great deal of time building a family of camera
profiles with different settings in order to determine the best profile for
the photo task at hand.
Pipeline Considerations
Once a camera profile or a series of camera profiles has been created, we
need to test them just as we did our scanner profiles. Once again, how
this is conducted depends on how you handle your digital camera files.
If you have been shooting RAW files, you would need to use the camera
profile inside the RAW converter application, assuming it supports ICC
profiles. If this were the case, you would start by setting the RAW con-
verter the same way as you processed the camera target file that built the
camera profile. At this point, you would attempt to process RAW data
using the profile and if everything works, as it should, the color appear-
ance of these files should be greatly improved. If the RAW converter
doesn't support ICC profiles then the RAW data will need to be processed
in a locked-down mode exactly as you processed the camera target.
Ideally, this can be done in such a way that you can bring processed high-
bit RGB data into Photoshop. Assign the camera profile and if necessary,
apply corrections to this high-bit data.
These two approaches are functionally similar to the scanner drivers
discussed in Chapter 4. Like testing a scanner profile, apply the new
camera profile to a number of representative images. If you are attempt-
ing to use one camera profile on multiple scenes, gray balancing can be
the key to consistency. It will be necessary to gray balance the camera
target when building the profile. Then, all subsequent images shot, even
in different lighting situations, would require that you photograph a gray
