[pure-silver] Re: Was Old paperandDefender... now The Hows and Whys Qiuz Show for Dummies: Whats the Mechanism?
- From: "mail1" <mail1@xxxxxxxxxxxxxxxxx>
- To: <pure-silver@xxxxxxxxxxxxx>
- Date: Sat, 1 Mar 2008 08:47:16 -0800
To paraphrase Neblette's Photographic Principles and Practice"
The three classifications of reduction or the removal of silver from the
photographic image are.
1. Subtractive. Reducers of this type remove equal amounts of silver from
all densities there by increasing the density range of the negative.
Subtractive reducers improve over exposed negatives, and positives, or for
removing fog.
2. Proportional. Reducers of this type remove from each density an amount of
silver which is proportional to the original density. Proportional reducers
are a means of reducing excess density and contrast due to overdevelopment.
3. Super Proportional. Reducers of this type remove a greater proportion
from the higher densities than the lower densities. This type reduces
density of overdeveloped negatives of contrasty subjects.
Photographic reduction is a process of oxidation where the reducer converts
the metallic silver into a silver compound which is soluble in water, in an
acid, or other suitable solvent.
Neblette continues on for another seven pages or so to explain the different
formulations, and uses for the above types of reducers.
Jonathan Ayers [mail1@xxxxxxxxxxxxxxxxx]
-----Original Message-----
From: pure-silver-bounce@xxxxxxxxxxxxx
[mailto:pure-silver-bounce@xxxxxxxxxxxxx] On Behalf Of Ray Rogers
Sent: Friday, February 29, 2008 10:25 PM
To: pure-silver@xxxxxxxxxxxxx
Subject: [pure-silver] Was Old paperandDefender... now The Hows and Whys
Qiuz Show for Dummies: Whats the Mechanism?
--- Don Sweet <don@xxxxxxxxxxxxxxxx> wrote:
> provided you use a cutting bleach rather than
> a proportional one...
Hummm...
that reminds me of a fuzzy area I would like to get cleared up...
Can anyone explain, propose or point to a possible mechanism for how the 3
kinds of reduction...
cutting, proportional and superproportional takes place...?
I am having a hard time visualizing how this can occur!
Ray
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