I've been playing around with black and white reversal processing. Right now I'm trying some old 16mm movie film and I'm seeing really thin dmax. Here is the run down on the chemistry. For first developer I'm using D-19 with 2g sodium thiocyanate. Bleach is chromate sulfuric. Then a sulfite clearing bath. Second developer right now is dektol. Then fixer. I guess my main question is what influences dmax the most in this type of process? There are a lot of variables here so I can't expect to pin it down exactly but some ideas might help. Using this exact same chemistry I have had much better results with a different film. Possibly my chemistry is getting weak, I don't know.