Rodinal film developer

Description

Rodinal concentrate — the oldest developer still in production, to a formula from 1891. Para-aminophenol in an alkaline solution, diluted 1+25 to 1+100 and used once. The sharpness it is loved for, and the grain it makes no attempt to hide.

What it does to film

Rodinal holds almost no sulphite, so it does not dissolve silver and does not smooth the grain — it develops it as it is. What it does instead is produce an edge effect: adjacent areas exhaust the developer at different rates, so the boundary between light and dark is emphasised. Hence its reputation for bite. On a slow film the result is superb; on ISO 400 the grain becomes part of the picture, and that is a decision to make before you start.

Dilution is the control

1+25 is faster and more contrasty, 1+50 is the everyday classic, and 1+100 stand development gives soft highlights and a very pronounced edge effect. One dilution, one film: the working solution is poured away and does not work twice. The concentrate, meanwhile, lasts for years — its dark colour is a sign that it is working, not that it has spoiled.

Questions and answers

Why is the concentrate almost black?

That is normal: para-aminophenol darkens in alkali over time and it does not affect how it works. Rodinal is one of the few developers whose concentrate outlives the photographer’s interest in it.

How many rolls will a bottle do?

The yield in each size’s name is for 1+50. At 1+25 it goes twice as fast, at 1+100 twice as far.