Graphics Programs Reference
In-Depth Information
using a flatbed scanner. I've had very limited success producing usable
printer profiles with such products and instruments. My advise is to bite
the bullet and purchase a Spectrophotometer or consider getting an
outside professional service to build profiles for you. If you must test the
waters with an inexpensive Colorimeter/scanner package, be sure you
have the ability to return the product if it doesn't deliver quality results.
Since a Spectrophotometer is the measuring instrument necessary to
build quality output profiles, what options are available? At the low end,
there are Spectrophotometers that expect the user to measure each patch
manually, one at a time. This presents two problems. First, if you have
to measure 900 or more patches, this can take an agonizingly long time.
Second, the likelihood that you might measure the wrong patch by
mistake is high. Yet another issue can be caused by the measurement of
a single patch. Having more than one measurement per patch and aver-
aging the data can often produce increased accuracy and thus better
output profiles. This is especially true with some substrates that have
rough surfaces like a Canvas paper for an ink jet printer or an output
device that has a course dot pattern. I have produced good profiles using
a one-patch-at-a-time Spectrophotometer but the time to read a repre-
sentative sample of color patches wasn't an effective use of my time.
There are situations where having the ability to measure a single color
sample is beneficial, which I'll discuss later.
There are Spectrophotometers that can measure a row of patches in
a single pass or what is known as a scanning mode. The user clicks a
button on the instrument and then slides the Spectrophotometer over a
row of patches. The Spectrophotometer scans all the patches, often taking
multiple readings per patch, and sends the data to the host software. The
X-Rite PULSE, the GretagMacbeth Eye-One Pro Spectrophotometer, and
the Avantes Spectrocam are three such devices. As seen in Figs. 6-1,
6-2 and 6-3, the user places the Spectrophotometer on a target and slides
the instrument over a plastic device that looks a bit like a slide ruler.
When the user gets to the end of the row and lets go of the button, the
Fig. 6-1
The Spectrocam.
