At this point, I think we can conclude that D316 will not fail with low-speed films, as DS-10 did. I've tested the following slow films:
Ilford Pan-F+, Ilford FP4+, Fuji Acros
All did fine in D316.

Yesterday, I ran some rolls of Delta-400 in both XTOL (7.5m) and D316 (15.75m), and compared them on the light-table. Measurements and loupes show results similar to Tmax-400: Compared with XTOL, D316 gives about the same film-speed, slightly finer grain and a little less sharpening. Here are the graphs of Delta-400 in both soups:

CurveDel400-D316-XTOL.jpg

As we've seen before, D316 also creates a higher shoulder, which I suspect is due to D316's stronger buffering. That will give better gradation in things like clouds, snow and white clothing. But this improvement is substantially better than what I've seen in other films. Any idea why? Using Ilford's recommended time of 7.5m, Delta-400 in XTOL gave a Contrast Index (CI) of only 0.50. But 0.58 is needed to print at grade 2, so this is a little low (grade 3?). In the graph, D318's CI is 0.52. I matched XTOL's CI so that I could compare grain, but I suggest using a little longer time to boost contrast.

Here are the times I have so far:

Tmax-400 ......... 12
Tri-X .................. 13
Acros ................ 13
Neopan-400 ..... 13.75
Pan-F+ ............. 12.25
FP4+ ................ 16
Delta-400 ......... 16.25

Today I'll be souping some Tmax-100.

Mark Overton