PC130 Variation on Ansco 130
Sandy King posted a recent bit to the Black and White Forum expressing a curiosity about glycin based developers and about glycin combined with ascorbic acid in developers. He got the usual collection of replies and formulae, none of which really addressed the inquiry very well. I got thinking about the subject, however, and I decided to try a few things. My first experiments were directed at Ansco 130 print developer. This well known formula is noted for its neutral tones and excellent gradation on most papers. One of my experiments produced a print developer worth sharing with you.
Water (52C) 750 ml
Sodium sulfite (anh) 50 g
Ascorbic acid 18 g
Sodium carbonate (mono) 78 g
Phenidone 500 mg
Glycin 11 g
Potassium bromide 5.5 g
Water to make 1 l
pH (measured) = 10.1
This looks a lot different than Ansco 130, but it is really very close to the original formula. Ascorbic acid replaces hydroquinone in about an equi-molar proportion, and phenidone replaces metol. It was interesting that the amount of sodium carbonate did not have to be adjusted to compensate for the acidity of the ascorbic acid. The buffering effect of the large amount of carbonate is obviously excellent. Phenidone is not quite as superadditive with ascorbic acid or glycin as it is with hydroquinone, and the amount was adjusted accordingly. In experiments with E-72 some years ago, I found that the highlights tended to be harsh and lacking in detail. I was hoping that the glycin and the additional phenidone would help correct that problem.
The developer was diluted 1 + 1 for use, and the prints were developed for two and one half minutes. Three papers were tried: Forma Variant 312, Ilford Multigrade IV RC, and Kodak Polymax II RC. In addition to regular prints, I printed a step tablet and compared the curves produced by Ansco 130 and the new developer.
Based on emergence times, the PC130 appears to be considerably more active than Ansco 130, but it gives slightly slower paper speeds. The difference is about a third of a stop for the Forma paper, nearly a quarter stop for the Ilford, and almost none for the Kodak.
Except for the speed difference, the curves for the Ilford and Kodak papers are nearly identical for the two developers. The Kodak paper shows a somewhat smoother toe. The Forma paper showed considerable differences, which are also apparent in the prints. In Ansco 130, the Forma paper had a very long toe with a sharp break to the staightline portion. In the new developer, the sharp break between the toe and the straghtline portion is gone, and the toe is smoother. Highlight contrast is noticeably increased. Dmax is also greater.
The preliminary prints show little difference between Ansco 130 and PC130. PC130 may actually have slightly better gradation. The highlights are a bit smoother and have a bit more contrast. The midtones and shadows retain the qualities of Ansco 130. Image tone is almost identical. PC130 definitely has potential as a fine print developer. I have not made any effort to optimize PC130. Some things to try in the future:
1. Decrease the bromide, possibly substituting benzotriazole for some or all of it.
2. Increase the glycin up to about 14 grams per liter.
3. Decrease the pH slightly, maybe to about 9.9.