Quote Originally Posted by Claire Senft
Try a shadow based exposure and try again with two 1dentical placements on Zone 2 or three and see if it helps. All of the articles appeared in the finest..my opinion..photography magazine extant. Photo Techniques. What else would one call a photo magazine that publishes those neat articles by Patrick Gainer? I should have been a bit more moderate in my statement and have said that it can add up to 1 stop of film speed.
I'll try your suggestions with meter placements on lower Zones. I did notice some improvement in shadow contrast in yesterday's experiments, but not a true increase in speed. The best printable negs from the perborate treated roll were those exposed at the same ISO--200 as the non-treated roll.

Although I've been a subscriber to Photo Techniques since its beginnings, I don't remember those particular articles, but since I've still got all the back issues, I'm sure I can find it. Of course, the fact that I can't remember something is no great issue these days. In my second half-century, my data bank is pretty full, and my apparatus for accessing long-buried data is becoming increasingly unreliable.