Quote Originally Posted by Rudeofus View Post
I do my test charts at 30C in order to speed up testing. Yes, if 7 minutes at 20C is indeed the correct processing time for Xtol stock and Tri-X, then I should repeat this test either with 6 minutes at 20C or 2 minutes at 30C. But looking at the contrast of this neg, I think the threefold increase in dev time alone doesn't explain the huge contrast I got.
Yes, thanks for noting.

10% less than Xtol 1+0 time is not correct for all films.

It seems about right for APX100 but some Acros I developed in W3 for this time was somewhat contrasty and overdeveloped.
I would expect about EI=80 for Acros with D-76, attached pics of a cable duct and some silver birch trees were taken at EI=125, have plenty of shadow detail overdeveloped in this way (in error).
The fact that Acros was overdeveloped does not mean that there is no speed increase with correct development. Chemically it is similar in composition to the former Paterson FX-50 but more concentrated in the working solution:

My theory is that these phenidone/ascorbate type developers kept in half full bottles usually fail because all the ascorbate is oxidized and/or the pH drops.
To get round this I use a lot of ascorbate that can cope with a lot more air and a lot of carbonate as there is a lot more acidic decomposition products to be buffered against.
Yes, if you get around to doing the test you mention it certainly would help to clear up the matter of the film EI vs some other developer.