Glycol and fog
This is the first time I experiment with a homebrew developer. I tried Pat Gainers PC-Glycol developer. I heated the ethylene glycol (antifreeze) and dissolved 100 gr of Ascorbic Acid and 2.5 gr of Phenidone A.
I exposed delta 100 and HP5+ from zone 0 to zone XI with a Nikon F4, and tested at 1+50 for 3, 6, 9, 12 and 18 minutes.
When measuring densities I zeroed on B+F. To my astonishment the exposed frames from zone 0 to III had uniform densities above B+F af about 0.4. Only after zone III the curves begin to rise.
I cannot explain this behaviour. Is it just fog? Then why don't I see it at unexposed parts of the film? And this way film sensibility would be minus 2 stops for both films. Is that normal?
Can anybody explain this to me?