Originally Posted by Steve Ruddy
I’m developing 120 FP4+ and switching from D-76 to HC-110. I have been using the massive developer chart time for stock D76/ASA125/@68 which is 8.5 minutes. The time for HC-110 is a listed as a time range so the same conditions suggest 7-9 minutes. Would it be safe to assume that using 8.5 minutes will give me the same results as D-76 at the same time, speed and temp?
Why are you using the Massive Development Chart instead of using the times that Ilford has determined through proper testing? Ilford's tech data for FP4+ gives times for both D-76 and HC-110 and while I have not used HC-110 for that film, my experience with Ilford's films is that most of the time, their recommendations are spot on.
Here's their FP4+ tech Data
The Massive Development chart is worthless. The times on it were contributed by people who may or may not be skilled workers; often they have multiple, very different times, for the same film and developer combination. Completely unreliable.
When trying something new, ALWAYS use the manufacturer's recommendations as a starting point. They're usually correct. That is especially true for Ilford and Kodak in my experience.
If the manufacturer doesn't have times for your film/developer combination, then try to find times from a photographer who has tested it and posted info on his/her testing and has sample images for you to see.
has my tested times for a number of films in D-76, Tmax Developer, Rodinal, and PMK. With Kodak and Ilford films, I am usually pretty close to the manufacturer's times for developers they give times for.