Digital BW, The Print

Bill,

This is interesting, I think the difference between 16 and 8 should be more obvious on big prints, did you try ?

Michel

----- Original Message ----- 
  From: BKPhoto@... 
  To: DigitalBlackandWhiteThePrint@yahoogroups.com 
  Sent: Saturday, January 15, 2005 3:24 AM
  Subject: [Digital BW] Re: 16 bit and printer output/info for Roy


  Roy-

  I pulled test prints through IJC/OPM and QRT. Same grayscale file (12x15 inch 
  image area). One print at 16-bit, the other at 8-bit. Tests were made with a 
  4000 using UC, on Epson Enhanced Matt roll paper.

  There are obvious differences between the RIP's, of course. The supplied 
  IJC/OPM profile did a better job of matching the on-screen image contrast and 
  density (I use Dot Gain 20% as my default working gray space). By adjusting the 
  QRT image using Ink Limit and Gamma, I was able to marginalize the differences. 
  The colorcasts provided by the two RIP's are also different enough to 
  influence my judgment.

  I cannot see any significant differences in the prints that I can 
  subjectively attribute to bit depth. There are differences, but very subtle. With IJC/OPM 
  the 16-bit file printed with a very small increase in contrast. You can see 
  this under a loupe. At normal viewing distance, the impression is that the 
  print is a bit sharper and slightly darker, which is to be expected. These are 
  small differences, but the kind that I learned to appreciate through many years 
  of printing in the wet darkroom.

  With QTR I see the opposite. The 8-bit file prints with slightly less density 
  and a bit more contrast. In my opinion, the 8-bit file is a better print, for 
  the same basic (and subjective) reasons I like the IJC/OPM 16-bit print. I 
  used the "cool Selenium" profile, by the way.

  I'm very interested to know what you make of this. My initial thinking is 
  that each RIP is doing its best work the way it was designed: IJC/OPM with 16-bit 
  and QTR with 8-bit.



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




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