Digital BW, The Print

In a message dated 1/14/05 10:28:11 AM, tyler@... writes:


> Long ago, testing with a different RIP, I did see a difference,
> sometimes. Since the RIP I use accepts hi bit in, I'll just stick with
> it to make sure I'm getting the best possible for now.
> It's working, and at some point it's more satisfying to make prints
> than tests.
> 

Guys-

I've been following this thread and would like to mention something that 
dovetails with Tyler's comments.

Recently I've been testing a number of RIPs (ColorBurst, ImagePrint, Bowhause 
and Lyson's Daylight Darkroom based on Bowhaus, and QRT) on a 7600 and 4000, 
both with UC inks. My initial interest was to compare the supplied profiles. 
The idea was to establish a baseline: what kind of print do these applications 
produce out of the box (I've built custom profiles for the ColorBurst RIP, 
using the i1 spectrophotometer and MonacoProof and compared those to the "canned" 
profiles, as well).

I ran a series of test prints with a healthy 8-bit grayscale file, another 
with a good 16-bit grayscale file. Both had 21-step tonal ramps attached, which 
was very helpful.

As you might expect, each RIP produced distinctively different prints. They 
all did a good job; each is an improvement over the OEM print driver. However, 
I've noticed a difference in the 16-bit test prints made with IJP/OPM (made on 
the 4000). It seems to do a better job with local contrast. Similar or very 
close tonalities separate better, giving the print an improved sense of overall 
sharpness and depth. It is definitely noticeable to the eye.

I have no idea if this is directly attributable to IJP/OPM's internal 16-bit 
architecture, and I have no way to objectively test this, but it makes 
intuitive sense to me. Better data in, better data out provided each link in the 
imaging chain does it's job properly and is managed properly. There could be many 
other factors, of course. It could be that the IJP/OPM's canned profile 
happens to match-up well, with the printer, ink and paper combination I used. Maybe 
the planets were in alignment. However, I'd also say that the IJP/OPM print is 
at least as good as those made with my custom profile. Not bad, especially 
considering the difference in cost and the time one has to invest in the 
learning curve.



Bill Kennedy
Associate Professor of Photocommunications
St. Edward's University
512/448-8680


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