Quote Originally Posted by David A. Goldfarb
Certainly with SXX, a dense negative should give good shadow detail, since the shadows will be well off the toe, and there's plenty of scale at the top of the curve to keep good highlight detail, as long as you're not trying to increase contrast through extended development, say, two zones beyond normal. Other films may just max out in the highlights before you get that far.

I wonder, though, if another factor may be at work having to do with Azo's reciprocity characteristics or something of that nature. A denser neg might just make it easier to get to Azo's ideal exposure time, whatever that may be.
The other factor that may be at play here is the characteristic curve of Azo. I read the reflection densities of my test which indicated the negative density range that Azo would accomodate but I did not plot curves for the paper. I could do that since I have all of the data. The thing that may be occuring is that the curve of the film could be interfacing with the curve of the paper in such a way that an unattractive compression may be occuring. I could certainly see that possibility with the shadows lying on the toe of the film's curve and then falling on the shoulder of the paper. That would be a recipe for flat shadows.