----- 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.