| There are several methods to convert digital images to black &
white, or more appropriately, shades of gray. Although your
results may not vary that much at first glance there is a big difference
when prints are made at a local photo lab.
Easy but less desirable methods to convert color images to grayscale
include 'Grayscale' and 'Desaturate' commands. They don't provide
control over highlight, midtones, and shadows and discard valuable color
information. This becomes a problem when printing at a color photo
lab. Since these labs use a color print process there will be an
ugly color cast, usually magenta, if the operator isn't experienced
enough to correct for it. Even with professional help there will
be some trace of color in the finished print. I would add blue and
cyan to grayscale images to compensate but the resulting print had faint
blue highlights.
The Channel Mixer in Photoshop is my preferred method for creating
good grayscale images that look and print great. The secret behind
this is retaining color information rather than discarding it
during conversion. In other words, you are working with a full-color
image that simply looks black & white. Color lab prints made
from these files look exactly like they do on screen. In addition
you are able to make an unlimited number of adjustments for highlights,
midtones, and shadows by moving individual color sliders. Be sure
to save your creation as a new file so the original can be used
again. |
