Agfa Scala is a gem, well it was until it was discontinued as Agfaphoto ceased the processing of this Black & White slide film. To simplify, the process involved a chemical fog causing standard B & W negative to inverse creating a positive. You can actually use a few standard B & W negative films and process them using a kit Foma produce to give a positive.
As I had five rolls of this film stored in the freezer since my undergraduate days I thought I might as well use them for the trip to beaches of Normandy. At first I was going to get the films processed as slides, there is only one UK based company providing a Black & White reversal process costing £15 per roll…!!! Hhmmm I think not. I decided to go with processing the rolls as standard negatives. After hours of reading through various forums on the multitude of possible chemical combinations and options and I do mean multitude; ID-11, Rodinal, Studinol, a mixture of the Rollei devs, mixing up parodinal (a paracetamol based Rodinol mix) and many others I decided to go with plain old Rodinol. The dev times were a bit hit and miss, even the Massive dev chart was a bit … well misleading.
So I just plucked some numbers out of my head… 13mins @ 18ºC with 20 second inversions every minute.