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| Part A | ||
| Water 165F/75C | 150 | ml |
| p-Aminophenol Hydrochloride | 10 | g |
| Potassium Metabisulfite | 100 | g |
| Part B | ||
| Cold water | 150 | ml |
| Sodium Hydroxide | 42 | g |
| Part C | ||
| Cold water to make | 1000 | ml |
| Mixing Instructions: Add chemicals in specified sequence. Always use cold water when mixing sodium hydroxide due to risk of heat reaction. Always wear gloves and protective goggles when mixing sodium hydroxide. Unlike many other two part developers you must mix both parts together to make the concentrated solution. Part A: Boil 150 ml of water, allow to cool to 160-170F/70-75C, pour into a thick glass or ceramic container. Add 1 gram of Potassium Metabisulfite, stir until dissolved. Add the p-Aminophenol Hydrochloride, stir until about 75% dissolved. Add the remainder of Potassium Metabisulfite, complete mixing. Part B: Pour 150 ml of cold water into a thick glass or ceramic container. Fill a large plastic pan with ice cold water for use as a water bath. Place the 150 ml container into the water bath. Add the Sodium Hydroxide, stir until dissolved. Final Mix: Allow both solutions to cool to 115-125F/45-52C before continuing, then very slowly add just sufficient amount of Part B to Part A to dissolve the pellet that initially forms. Next, mix the two solutions together in a new container and add cold water to make 1000 ml. Let the solution stand in a cool place for 48 hours, then filter through a doubled-over paper towel into a suitable container. Concentrate keeps for a very long time if dispensed into a tightly closed bottle with as little air as possible. It is recommended not to keep it all in one bottle, but dispense into smaller ones, according to your projected needs. Initially the concentrate has pale lavender color, it darkens with storage with little impact on performance. |
| Dilution: 1+4, 1+9, 1+19 |
| Usage: Starting point development time varies by dilution. The approximate equivalent developing dilutions compared to those published for Rodinal are: 1+4 = 1+25, 1+9 = 1+50, 1+19 = 1+100. |
Notes The current commercial formula for Rodinal is unknown and there are many different published variations. The formula published here is a tested substitute which will provide results almost identical to Rodinal, but must be used at different dilutions to the commercial product. Some variants of this formula call for adding potassium bromide; however, this developer will produce very little fog with current films. Increased fog may be encountered in developing of outdated films. In this case no more than 0.25 g/L of potassium bromide may be added. Mixing this formula is recommended for experienced users only. |
