Quote Originally Posted by Michael R 1974 View Post
Hi Mark - regarding the most recent scans, I'm having a hard time finding any consistent differences one way or the other (essentially the same experience I had with the first scans). And I know your curves are essentially identical. My two cents: given the magnification, for practical purposes any differences in apparent graininess or sharpness between the concentrate and XTOL with this film are trivial.
Michael, thanks for responding! Your observations agree with mine, but I don't trust mine because I'm biased. At least with HP5+ and TMY2, this concentrate is achieving the goal of matching XTOL's grain, sharpness, curves and dev-times. But as a non-aqueous concentrate, it should last much longer. I'm encouraged, and will run more tests with it.

@Kirk Keyes - Well actually (swallowing hard), I do keep this in my food-refrigerator. Unless there are small children in a household, well-marked bottles of chemicals will never be accidentally ingested. And even if they were ingested, these chemicals are nearly non-toxic, so little harm would result. Some other chemicals, on the other hand...

@relayer - I like your ideas of potassium sulfite and reducing sulfite. In fact, I've tried both. This concentrate is intended to act exactly like XTOL, but I want to explore your ideas more to make developers that are different from XTOL. One reason I avoided potassium sulfite is I thought it was difficult to obtain; can you buy it in Ukraine?

Mark Overton