Thanks to then enlightening work of Pat Gainer, I decided to try adding sodium ascorbate to FG7. For those who are familiar with FG7 it is, much like Rodinal, very sharp but kind of grainy. For years it has been recommended that one add sodium sulfite to the formula. Well, it looks like sodium ascorbate is even better. I'm seeing significantly finer grain, remarkable sharpness and very smooth tonality.

1oz. FG7 + 1/2tsp sodium ascorbate + 14oz water (I used distilled.) Delta 400 @ 400: 9 minutes at 70, one minute initial agition, followed by 10"/min.

-- Ted Kaufman (writercrmp@aol.com), April 01, 2002

Answers

On a side note.....I've found FG-7 grainy for most fast films but remarkably finer grain with FP-4. Also, I never add Sulfite as it only 'smears up' the grain. I'll certainly try the ascorbate with it! Actually, what I have is Ascobic Acid. Is 'dose' the same? Thanks, Howard

-- Howard Posner (hposner1@swarthmore.edu), April 01, 2002.

Howard, absolutely do not use ascorbic acid with FG7! It is too acidic and it will render the developer nearly useless. Either find sodium ascorbate or use sodium bicarbonate to reduce the acid value of ascorbic acid.

I think it takes about 1/2 the amount of sodium bicarbonate to do the trick--1/4g sodium bicarb to 1/2g ascorbic acid. You must first dissolve the bicarbonate, let it sit till the fizzing stops, then add the ascorbic acid. I can't vouch for the success of this method, however. If I were you, I'd go to the healthfood store and get sodium ascorbate.

-- Ted Kaufman (writercrmp@aol.com), April 01, 2002.

'K.

Thanks

-- Howard Posner (hposner1@swarthmore.edu), April 03, 2002.

Ted,

What experience do you have with Gainer's formula and TriX? I recently did some preliminary testing at 1:1:6 and came up with ASA 1/2 stop slower than that of Xtol or HC-110. 200 vs.300. Any comments? I used the original formula posted here. Howard

-- Howard Posner (hposner1@swarthmore.edu), April 03, 2002.

Howard, I never tried Tri-x in Gainer's vit-c. I've used it mostly with Delta 400 and some with TMX and HP5+. I'm sure Tri-x would look excellent in Gainer's formula.

-- Ted Kaufman (writercrmp@aol.com), April 03, 2002.

WRT using Ascorbic acid in place of Sodium Ascorbate: The proprtions given by Ted Kaufman are right, but using Sodium bicarbonate to convert Ascorbic acid isn't a good idea IMHO. It'll result in the release of Carbon dioxide gas, which will partly dissolve in water to give Carbonic acid. This means some of the alkalinity of the developer will again be neutralised, and the dissolved CO2 may outgas on the film, causing pin marks or streaks.

A much more chemically elegant way to do the conversion is by using Sodium hydroxide. The byproduct in this case is simply water; the chemical reaction being:
C6H8O6 + NaOH -> C6NaH7O6 + H2O
The correct proportions to use are 2 parts of anhydrous Sodium hydroxide to 8.8 parts of Ascorbic acid; giving the equivalent of 9.9 parts (close enough to 10) of Sodium Ascorbate in solution.

The use of a pH meter or an indicator paper to obtain a truly neutral solution is really the way to do it, but if you use proportions of 9 parts of Ascorbic acid to 2 parts of Sodium Hydroxide, you can be fairly sure that the solution will have just a slight excess acidity. Not enough to upset the pH of a developer beyond normal tolerances.
An excess of caustic soda would cause a greater change in alkalinity, and therefore processing time.

-- Pete Andrews (p.l.andrews@bham.ac.uk), April 08, 2002.

I have used both baking soda and sodium hydroxide. There is a lot of effervescence if you use only a small amount of water when you mix the ascorbic acid and the baking soda. If the water is a little bit warm the potion will go flat very soon. (It could actually be used as a potion.)Then you can add it to the mix and get consistent results. The only real advantage of bicarbonate is that there is less effect from an overdose, both for you and for the developer.

-- Patrick A. Gainer (pgainer@rtol.net), April 12, 2002.