Originally Posted by colrehogan
I ran into problems with fogging the other day that I thought were related to the sensitizer and developer being at very dissimilar pH values. The attachment shows the difference between the test plate of the mannequin after I adjusted the pH and a detail of a portrait from earlier last week. Both were done on black glass with the same light, and lens.
The gray veiling that is evident on the portrait is what I was trying to get rid of. The mannequin shot from yesterday has much better contrast and is also warmer, both effects which are desirable. The mannequin image had the sensitizer and developer at roughly the same pH and I used an ammonium thiosulphate-based fixer on that plate for the first time. It cleared and reversed the image in about 15-20 seconds which was much quicker than plain hypo and in about the same time as the KCN would act.
So, the test plate chemistry changes did what I was hoping.