I just worked up some tests of three films in Pyrocat-HD (metol version) and got some interesting results, some useful, some maybe no so useful.(posted 8058 days ago)That "standard" is D-76H 1:1 or 1:3, rotary processing, which yields virtually dead-straight curve shapes with the tested films.
HP5+ takes on a distinct S-shaped curve, showing (for normal midrange contrast) decreased shadow contrast and decreased highlight contrast. Although the shadow compression isn't really bad, it may require more exposure for good shadow contrast. Shouldering begins down in the useful range but is mild and rounded. Speed for .10 DU above fb&f is EI 200.
TMX is straight out to about Zone VIII, after which it rolls off into a rounded shoulder, much more so than HP5+. Speed is EI 64.
Acros is the odd one, straight out to about Zone XI, then abruptly going _upward_ as it does in other developers. Not the slightest hint of a shoulder; in fact, quite the opposite. Speed is EI 50.
The neg color is brown but the stain isn't near as heavy as, say, PMK, and may not have a tremendous effect when printing on VC paper although I do expect at least a little reduction in highlight contrast by the stain alone.
So...a very significant shoulder appears in two of the films by choice of developer alone.