[quote="Dave Swinnard"]Hi Sandy

I've just mixed my first batch of Pyrocat HD and was rereading your article with an eye to guestimating a starting dev. time for a test roll of Acros. I referred to the CI charts, specifically Fig. 22 and noticed that though it was a BLUE chart the dilution was 2:2:100 rather than the 1:1:100 indicated for silver printing. (your notes prefacing the charts indicated the BLUE captioned charts are intended for silver gelatin processes.)

Does Figure 22 in fact refer to the 2:2:100 dilution (and CI's appropriate for silver printing)?


The captions are correct. The 2:2:100 dilution is the only test data I have for this particular film, and it was in fact provided me by another BTZS/Pyrocat-HD user since I don't use this film. Since the CI at the shortest time of develoment from this test is about 0.52 the information would be useful for regular silver papers only in N+ lighting situations.

BTW, the Blue light readings should also be used fo calculating develoment times for AZO, which is a form of silver printing.