This image is from a roll of HP5+ that I originally intended to develop in Perceptol. I had metered the roll at 320, as is my usual practice with Perceptol, but found that I had run out of that developer when it came to processing time. I turned to Ilfotec HC as a replacement; after giving some consideration to possibly curtailing development a little, I plumped for 6.5 minutes, which Ilford say is good for HP5+ exposed at 400.
I had used HC mainly with 5x4 negs up until this point, and it strikes me as a flexible developer, with a good mix of qualities. The negs are good, with a nice open tonality, and they will make a flexible starting point for darkroom printing. My initial impression is that they are not quite as sharp as Perceptol negs. Perceptol needs a little more work because it has to be mixed from a powder (HC is a liquid, ready to be diluted), and development times are quite long when film speed is down-rated.
Still, it is pleasing to have the quality of Perceptol confirmed by comparison, and I shall look on HC as a sound stand-in for similar circumstances. I'm happy to embrace such a detour because there is always something to learn.
Roy Bijster asks a great question on Twitter: 'I am a bit confused by "a longer development time for downrated film". Downrating = overexposing, so why the longer dev time?' I think I could have been more clear; I suppose this post was in note form, really. The answer is that Perceptol is a speed reducing developer, i.e. one loses speed by using it. A sort of 'penalty', in exchange for great image quality. With HP5+ rated at 320, the time using Perceptol stock+1 is 18 minutes. That's the figure I have in mind when I'm comparing to the much shorter 6.5 minutes of HC, for the same film rated at 400.
Normal practice, which Roy alludes to, is to reduce development when 'overexposure' is used. That's why I wondered if I shouldn't cut the stated 6.5 minutes for HC because I had exposed at 320.