Quote Originally Posted by Michael R 1974 View Post
Strange, I've not found Delta 100 to have a long toe in any developer I've tested it with. In developers including D-76, XTOL and even Perceptol I've found its curve to be nearly identical to that of TMX, with Delta having only a very slightly longer "toe" (and I mean a really small difference), and slightly higher highlight contrast. If developed in DDX, Delta does slightly better on speed and toe contrast than in other developers.
I rechecked my numbers, and indeed they say that if you use a speed point of .1 over b+f, the speed is well over 100. I interpreted that to mean a longer toe. Here are most of my Delta 100 graphs:

CurveDelta100-XTOL.jpg

XTOL is overdeveloped because I used the DigitalTruth time of 8 min instead of Ilford's 7.5 min.

A side-topic: The two curves for D316 were exposed and developed identically in all respects, including agitation-times of 10 sec each minute. However, I used vigorous agitation for the blue graph and gentle for the green. The vigorous agitation pulled up the shoulder, and had no other effect on the curve. As somebody said, "agitate for the highlights".

Mark Overton