Pain Reliever Rodinal & Other Chemistry · Заметки

A recipe of B&W developer from Jay Javier @ Soviet Camera Group (original recipe by David Qualls). Paracetamol-based version of Rodinal:

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I posted the formula at the zenit list as I found it from another newsgroup. However, I've modified it a bit -

30 tablets, paracetamol 500mg (white pills are better- the colouring (often orange) can mask the reactions as paracetamol is converted to rodinal);
50 grammes sodium sulphite anhydrous;
20 grammes sodium hydroxide (lye) flake;
3...5 grammes potassium bromide
water qs to 250 ml

Crush with a mortar and pestle (wash THOROUGHLY after use if you've used one from your kitchen) the pills until they become rough powder.

Mix dry the crushed pills with sodium sulphite and add about 200 ml water. Water should be about 25...30C. The solution will be very cloudy and murky white. Stir vigourously until the pills and the sulphite are dissolved. Then add the lye. The solution will remain murky and may thicken up slightly. The solution colour may also change - darkening will be from slight to significant. This is normal. Add bromide. The bromide wasn't in the formula I found, but it's part of the many DIY rodinal formulae. I found that the bromide will also reduce the tendency of this developer to cause a bit of fog some films. I did not use bromide initially, and some films I tested came out a bit grey in the 'clear' areas. Adding bromide to the concentrate had the the succeeding films develop 'cleaner'.

The developer needs about 2 days to "cook", The solution will form layers on standing, and should be shaken thoroughly before drawing off portions for dilution. Crystals may form at the top, and these should not be removed, but rather mixed back into the concentrate. The pill's starch vehicles need not be filtered- the concentrate need not be filtered at all before use. These won't affect anything, and even at dilutions of 1+25, the working solution doesn't look murky at all.

You can apply 'real' Rodinal dilutions and times and temperatures for using this paracetamol rodinal. The negatives I developed in this paracetamol rodinal developer looked the same in every bit as the negatives I got when I developed these in real Rodinal, using Rodinal dilutions.

The developer, according to the formulae published in the net will darken greatly with time. My concentrate is just a week old, and shows no dramatic darkening yet. According to the same sources, the developer will turn as dark as coffee -just like Rodinal - and if its just like the real thing, should last as long too.

UPD: Here's a site with many recipes: Jack's Photographic and Chemistry Site - Black-and-white photographic formulas & chemistry: http://www.jackspcs.com/.