On my last post I mentioned that something very strange happened with an Agfa APX 400 pushed to 1600. I went through the process over and over in my mind trying to figure out what went wrong.
It turns out that I missed the most obvious thing.
I was developing two films, one HP5+ and the Agfa APX 400 pushed to 1600.
The dev. time for the Ilford was 8 minutes and the dev time for the Agfa was 15 minutes.
I had both rolls inside the tank at the same time. After 8 minutes I poured out the developer, opened the tank and toke everything out. The Ilford HP5+ went to the stop bath and the Agfa went back in the tank. I poured the developer back in and developed the Agfa for 7 more minutes.
A much more knowledgeable friend pointed out that the result was a Sabatier effect.
I did not know what a Sabatier effect was so I googled it and here it is.
It’s not solarization, it’s something different.
I must thank my friend Augusto da Eira for the lesson.