Interesting article, Sandy.
I don't know if you ever heard of the CW-C2 developer. This is a developer
that had been designed for holographic emulsions (basically with Agfa's 8E75
and 8E56). I had been introduced by Cooke/Ward (Cook/Ward,
Reflection-hologram processing for high efficiency in silver-halide
emulsions, Applied Optics Vol. 23, pp.934-941, 1984).
It is formed:
A
Catechol................................20g
Ascorbic acid........................10g
Sodium sulfite.......................10g
Urea.....................................100g
Dist. water................................1L
B
Sodium carbonate................60g
Dist. water................................1L
By the way, the stain formed by that developer equally played an important
role for those emulsions: it served to mask the scatter from the relatively
large (~40nm) grains...
Martin
From: "Sandy King" <sanking@CLEMSON.EDU>
To: <alt-photo-process-l@sask.usask.ca>
Sent: Thursday, March 04, 2004 6:26 AM
Subject: Re: Fortepan
> John,
>
> The stain produced by Pyro developers is a UV blocker and results in
> more contrast because it is greater in the highlights than the
> shadows.
>
> This is explained in some detail on p. 3 of my article on Pyro
> developers. Go to http://unblinkingeye.com/Articles/PCat/pcat.html
> and for the question of the impact of stain with different processes,
> which is really quite complicated, see page 3.
>
>
>
> Sandy
Received on Sat Mar 6 22:56:23 2004
This archive was generated by hypermail 2.1.8 : 04/01/04-02:02:04 PM Z CST