Quote Originally Posted by mdm View Post
Used 1/2 my usual exposure and have a good 10 steps on a 21 step stoufer, obviously underexposed with no good black. It looks very much like 4 or 5% Ammonium Dichromate to me.

[...]

3rd transfer=20 min exposure (still going), 1st was 3 1/2 min for 10 steps, 2nd was 9 min for 13 steps, no black. I have another tissue sensitised at double the rate to try.

20minutes is coming close to a good black, 15 steps. My normal exposure with digital negs and 2%AD is 9min, that would be contrastier than this diazo.
David--

I'm glad to hear that your first attempts worked out well for you.

What light source are you using?

--Greg