Quote Originally Posted by psychfunk View Post
This evening my sister gave me a roll of 120 film labelled HP5+ so I could process it for her.
I souped it in HC-110 dilution H for 10.5 minutes, agitating once a minute (standard practice for me).

It turned out to be Delta 400...and the negatives turned out absolutely fine. Not a problem.
I looked for dilution B on Massive Dev Chart, which says 7.5 minutes, and doubling that for dil. H would give 15 minutes...

So, to what extent is accuracy actually required when processing film? Was it to do with the dilution of my developer?
If you print on multigrade paper, or have an extensive range of graded paper on hand, there is like a 30% plus or minus leeway with development times. How much leeway you actually have depends on the scene's range and your usual paper grade.