Sodium Sulphite in Rodinal : LUSENET : B&W Photo - Film & Processing : One Thread

Just read about this at 'Minox,Metol and Macintosh' but no specifics. Could anyone tell me their experience's of using this combo. Films, times, grams per 1-100 rodinal, results. Ta, Patrick.

-- Patrick Doyle (, December 12, 2001


Ahem,...also does anyone know the recipe for Diafine. Thanks, Patrick.

-- Patrick Doyle (, December 12, 2001.

Pat Gainer has been working on some very interesting uses for l- ascorbic acid, one of which is adding 4g/L to working dilutions of Rodinal. This has the effect of sodium sulfite--finer grain--without the attendant softening of the grain structure as sodium sulfite would (provided you used enough of it to lessen Rodinal's prominent grain).

-- Ted Kaufman (, December 12, 2001.

The addition of sulfite is, shall we say, a continuum.

As little as 10g/L will add up to 2/3 stop speed to fast films or to put it more accurately, restore speed lost from the film's nominal EI. I've found no significant effect on the speed of slow films.

More sulfite, up to around 50g/L, can provide a little less graininess but it's pretty subtle and again there'll be little effect on slow films.

If you already have established development times for Rodinal just use those as a starting point.

If you don't have a scale, a full plastic 35mm film cannister is approximately 50g of sodium sulfite.

-- John Hicks (, December 12, 2001.

I've been adding sodium sulfite to dilutions of Rodinal as follows:

For a 1:100 dilution, I mix 300ml water with 30grms(4tsp.) of sulfite and add 3ml of Rodinal. This is a 10% solution. I usually follow Agfa's recommended time/temps and adjust from there. I know this is a lot more than most people recommend, but, it works. You can see that the grain in a film like APX400 becomes finer with a grain focuser. Unfortunately, this will not make the grain disappear, so don't expect ss to work miracles, or anything else either! Another observation I have is that there is really minimal effect on sharpness when ss is added. Rodinal at high dilutions is extremely sharp. The problem as I see it is that Rodinal may not be a good choice of a developer for 35mm fast films at any dilution with any additive. The price for sharpness is grain, albeit, very nice grain. With slow films, Rodinal is king, and, with larger formats than 35mm, wow!


-- Jeff Novick (, December 13, 2001.

With slow fine grain films there is no advantage to adding Sodium Sulfite to Rodinal. If you want a developer which will give similar results with slow films but which can be used well with Sodium Sulfite for fast films, try Edwal FG-7. It is typically used 1:15 with or without Sodium Sulfite so you only need 1/2 ounce for a roll if you use a tank which requires 8 ounces of working solution. FG-7 keeps much longer than Rodinal once it is opened.

Jeff Adler

-- Jeff Adler (, December 27, 2001.

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