[pure-silver] Re: Polycontrast Paper Performance / Cold lite

  • From: "Richard Knoppow" <dickburk@xxxxxxxxxxxxx>
  • To: <pure-silver@xxxxxxxxxxxxx>
  • Date: Mon, 18 Oct 2004 14:45:49 -0700

----- Original Message ----- 
From: "J.R. Stewart" <jrstewart@xxxxxxxxxxxx>
To: <pure-silver@xxxxxxxxxxxxx>
Sent: Monday, October 18, 2004 11:06 AM
Subject: [pure-silver] Re: Polycontrast Paper Performance / 
Cold lite


> Remind me, Ralph, please: "factor of factorial 
> development"? And why does it
> apply only to fiber based paper? I don't recall seeing 
> that described
> anywhere... (not in your book is it??--if so just tell me 
> and I'll find
> it.).
>
> In a related post I made this morning, I reported a 
> significant difference
> between Ansco 120 and Anso 130M on the same paper. I 
> wonder if the small
> differences in paper response apply to developers of the 
> same class, e.g. MQ
> developers. Ansco 130 replaces HQ with glycin. It really 
> has a longer scale
> in my hands. It may also be due to my use of benzo as a 
> restrainer in my
> paper developers instead of Na bromide. Don't know.
>
> Jim

   Agfa/Ansco 130 does not replace MQ with Glycin but adds 
Glycin in addition to MQ. Without the Glycin it is very 
similar to Dektol or to Agfa 125, which was the Ansco/Agfa 
equivalent of Kodak D-72 or Dektol.
   Here are the two formulas for comparison.

Kodak D-72 Stock Solution (Identical to Dektol)

Water (at 125F or 52C)                    500.0 ml
Metol                                       3.1 grams
Sodium Sulfite, dessicated                 45.0 grams
Hydroquinone                               12.0 grams
Sodium carbonate, monohydrated             79.0 grams
Potassium bromide                           1.9 grams
Water to make                               1.0 liter

Kodak recommended dilution per the material being developed, 
varying from 1:1 to 1:4. 1:2 is about right for most 
materials but capacity is greater at 1:1


Agfa/Ansco 130 Universal Paper Developer Stock Solution

Water (at 125F or 52C)                    750.0 ml
Metol                                       2.2 grams
Sodium sulfite, dessicated                 50.0 grams
Hydroquinone                               11.0 grams
Sodium carbonate, monohydrated             78.0 grams
Potassium bromide                           5.5 grams
Glycin                                     11.0 grams
Water to make                               1.0 liter

Agfa recommended using the developer at 1:1 but stated that 
it could be used from full strength to 1:2

   Ansel Adams modification was to add Benzotriazole to the 
above and reduce the amount of bromide. He did this to 
affect the image color. Adams wanted neutral or slightly 
cold (blue) image color and found that Dektol gave him 
slightly olive (green) tones with many papers. Developers 
like Dektol or D-72 will do this on some papers especially 
when used for a time, perhaps because of the increase in 
bromide. Benzotriazole tends toward neutral or cold tones so 
replacing some or all of the bromide in a developer will 
shift the image color somewhat, just as in increasing 
bromide content will tend toward warmer tones.
   The presense of Glycin in 130 may also have an effect on 
image color but I am not certain in which direction it 
tends.
   From the formulas it appears that one could make 
something close to Agfa 130 from Dektol by adding Glycin and 
some additional bromide to the mixed stock.
   Glycin is added last because it dissolves better in 
alkaline solutions.

---
Richard Knoppow
Los Angeles, CA, USA
dickburk@xxxxxxxxxxxxx 

=============================================================================================================
To unsubscribe from this list, go to www.freelists.org and logon to your 
account (the same e-mail address and password you set-up when you subscribed,) 
and unsubscribe from there.

Other related posts: