Assume I'm well away from the toe and shoulder on a straight-line film. If I change the exposure by 1 stop (0.3 log units) and the density over fb+f on the developed negative increases by 0.15 log units, does this correspond to a contrast gradient of 50%? Or is this view too simple-minded?
Why am I asking? I needed to use up a half-roll of TMY2 in my Mamiya 7 so I exposed a gray card in 1-stop increments from metered, i.e. "Zone V", down to Zone I by changing the shutter speed only. I observed a 0.1 difference between II and III, III and IV, and IV and V, which to my feeble brain suggests a gradient of 33%. The difference between I and II was less, about 0.06, which I attribute to toe. Processing was in Pyrocat-HDC in glycol 1+1+100 for 14 minutes at 70F. There was plenty of solution (650ml) for a single roll of 120 in a 2-roll Nikor tank with an empty reel on top. FB+F was 0.2.
I seem to have no issues printing negatives processed as above using the same batch of Pyrocat. I used a Heiland TRD-2 densitometer and the calibration readings for both transmission and reflection exactly matched what's marked on the calibration cards.
Why am I asking? I needed to use up a half-roll of TMY2 in my Mamiya 7 so I exposed a gray card in 1-stop increments from metered, i.e. "Zone V", down to Zone I by changing the shutter speed only. I observed a 0.1 difference between II and III, III and IV, and IV and V, which to my feeble brain suggests a gradient of 33%. The difference between I and II was less, about 0.06, which I attribute to toe. Processing was in Pyrocat-HDC in glycol 1+1+100 for 14 minutes at 70F. There was plenty of solution (650ml) for a single roll of 120 in a 2-roll Nikor tank with an empty reel on top. FB+F was 0.2.
I seem to have no issues printing negatives processed as above using the same batch of Pyrocat. I used a Heiland TRD-2 densitometer and the calibration readings for both transmission and reflection exactly matched what's marked on the calibration cards.