RE: Digital negative novice needs help.

My understanding is that:

To get full 256 tones when using

a 3600dpi imagesetter (for instance),

the screen resolution should be 3600 / 16 = 225lpi (remember, 16x16 =
256),

and the computer image file should be at least 225 x 2 = 450 dpi
(actually x 2.5 is better, this is explained in a the sampling theorem
by someone named Nyquist) to get the best quality / detail.

If you were using a ... lets say 360 dpi screen, then the maximum
possible tones would be 3600 / 360 = 10 -> 10 x 10 (square) = 100
only...

Regards,
Loris.

-----Original Message-----
From: BOB KISS [mailto:bobkiss@caribsurf.com]
Sent: 20 Nisan 2006 Perşembe 15:42
To: alt-photo-process-l@usask.ca
Subject: RE: Digital negative novice needs help.

DEAR LIST,
Am I right that the # of lppm also influences the possible number of
values
(tones) that a medium can reproduce as well as the resolution? Yes, I
know that digital printing varies the dot size to produce various tones
but, it is a basic principle of info theory that the possible number of
tones that can be produced is proportional to the number of pixels per
unit area in the final image. This was similar in film technology; not
only did fine grain film (or larger format film for the same final print
size) allow the reproduction of finer detail but also the reproduction
of more possible tones. Sooooooooo, am I right that BOTH lppm AND
possible dot sizes at that line frequency influence the possible number
of tones that can be reproduced with that medium regardless of whether
or not one can resolve each pixel visually?
                CHEERS!
                        BOB
Received on Thu Apr 20 07:59:48 2006