Re: Best CI for process

From: Sandy King <sanking@clemson.edu>
Subject: Re: Best CI for process
Date: Sat, 01 Oct 2005 16:15:35 -0400

> If you do the former you will see, beyond any
> shadow of a doubt that what you claim, i.e. CI of 1.45 and true
> density range of 3.0 or more, is an impossible proposition for most
> modern films.

I agree. CI of 1 is already difficult or doubtful, even in Kodak D-11
developer, which is a classic favorite for continuous tone high
contrast developer.

The only way I can think of to obtain higher contrast is to use
hydrazine nucleating agent and amine contrast booster, like they do in
rapid access type document films. You could also use hydroquinone-only
lith developer but those distort the fine details of the image too much.

Films I know to achieve CI well above 1 are Ektagraphic HC and
Kodalith Ortho 6556 Type 3. The same emulsion was available in sheet
sizes as well. (But I think all of them are discontinued.) This
emulsion is very susceptible to dichroic fog in fine grain
developers, unless diluted.

Arista APH film is also capable of CI well above 1. (BUT this film is
very difficult to develop to usual negative contrast without losing
good image quality.)
Received on Sat Oct 1 14:29:55 2005