Wayde Allen (wallen@boulder.nist.gov)
Wed, 13 Jan 1999 09:05:41 -0700 (MST)
I forwarded the question about the size of the silver grains in T-Max to
an acquaintance of mine who I thought might have an answer. The
following is his answer. I have not checked his numbers.
Hopefully this is of some interest or use to you.
- Wayde
(wallen@boulder.nist.gov)
---------- Forwarded message ----------
Date: Tue, 12 Jan 1999 21:42:25 -0700
From: Randy Little <rlittle@rslittle.com>
To: Wayde Allen <wallen@boulder.nist.gov>
Subject: Re: Continuous Tone? (was Re: Pt/Pd vs Gum???) (fwd)
> I'm curious as to the "size" of the silver grains in a negative, say T-MAX
> 100.... in terms of comparison to an inkjet or imagesetter, what would the
> resolution of such a black and white film be?
I would guess that T-Max 100 has a grain size of around 30 microns. But
Kodak will tell you the exact number. The best Image setter in the world
does about 36,000 dpi but you can not compare since that is 36,000 dots in a
half tone screen. The screen may be only 300 lpi which is where the number
really matters since the screen is what most people can see anyway. It is a
little complex to try and explain over email. The only true comparison
would be stochastic image setters to film since the pattern created is very
much a random gathering of silver (well random with in the exposed areas
where the silver is exposed.)
The resolving power of tmax 100 is
TOC 1.6:1 is 63 lines/mm or (1600 lines/inch)
Toc of 1000:1 is 200 lines/mm or 5080 lines/inch
So Tmax can do upto 5080 lpi
and the best image setters are around 300 lpi
Even with average normal contrast of with a gamma of about .6 it basically
is WAY beyond what any printer is capable of. Now what you and I can see is
a whole other ball game.
I could make an 4x5 LVT at 2080 dpi and make a 30x40 and it would look
exactly like a print from a silver(dye based) Chrome. with your unaided eye.
-- Randy Little R.S.Little Studio Photography & Digital Imaging http://www.rslittle.comRepresented by:
Carol Guenzi Agents http://www.artagent.com
Jim Zaccaro & Assoc. http://home.earthlink.net/~jimzacc
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