B&W reversal first developer

Description

The first bath of the reversal process: it develops a negative image and dissolves silver at the same time, so that exactly enough halide is left for the positive to come.

Why it is not an ordinary developer

It contains a silver solvent — thiocyanate. That washes away developed silver along with the fog, and how cleanly the highlights of the finished slide read depends on it. An ordinary negative developer does none of this, which is why reversal in one gives a grey, listless positive.

Time is the control

First development time is the main lever of the whole process: longer development means a lighter slide, shorter a darker one. That is the opposite of the negative process, and it is where most mistakes happen. Follow the instructions and adjust after the first test roll.

Questions and answers

Could D-76 be used instead?

It can, but the result is worse: with no silver solvent the highlights stay dense and the slide comes out dark and grey.