To those using fast developers/high concentrations, such as Ilfotec HC; bear in mind that such chemicals are primarily designed for speed and convenience, over image quality. During my time at college, I learned that such chemicals weren't actually all that good, if you were at all bothered with ultimate image quality from your negs. Even at 1+31 dilution, HC wasn't great. but then I read up on the subject, and learned that reducing the concentration, and extending the development time; gave much better results; improved tonal range, better acuity?sharpness, and just a nice overall 'look'. Doing so does increase the amount of grain you get, but personally I love that look. The problem with quick developers is that you don't have such control over development, and need to be quick when pouring out dev and pouring in stop etc. For eg; HC @ 1:11 @ 24ºC gives a dev time of just 55 seconds for HP% @400ISO. That's way too quick to be able to control development properly (such dilutions are used for lab developing more than 'home' devving). Even the more 'standard' dilution of 1:31 still only gives a time of 9'30", which isn't to bad, but still not great for IQ, I found. I progressed to better chemicals, such as ID-11,, which when mixed up to 1:1, give a much better developing time of 13 minutes, so a lot more leeway. The chemicals are working more gently, and the whole process being slowed down, really benefits the final result. I used a 1:3 dilution, at 20 minutes, which gave me superb results. Deeper blacks, proper nice white highlights, much better tonal range, greatly improved sharpness, and just a much nicer overall look to pictures printed up. Printing was a far easier process as a result, less faffing required to get those tones in across the image. For pushing film, I found Microphen to be excellent; HP5 @1600 ISO did require a 30+ minute or so dev time though! Ilford don't recommend using such dilutions and long times though, as it's harder to maintain constant temp in the tank, and you can suffer reciprocity failure (I think, my memory is hazy now), requiring the time to be extended further. Meh. It worked for me! But it is a matter of real trial and error.
My college used HC 1:31 cos it was cheap, and meant students weren't developing for so long, allowing more teaching to be possible. Understandable. But I'd encourage any keen home developer to look into the alchemy of developing film, because your photography can really benefit from this.
Oh; and one of the most important things I learned was: wash your film properly. None of this 3x30 agitations in the tank; let it sit in running water for at least 20 mins or so. Because if you actually want to still be able to print from those negs in 20+ years time, if you haven't washed them properly, they'll be terrible, as the emulsion will degrade quicker the less it's been washed. I've got properly washed negs that are really starting to degrade a bit now; the poorly washed ones are now mostly virtually unprintable.
If you care; take your time. Don't rush things.
Forgot to mention; extending development time also requires less agitation. So instead of agitating every 10, or 30 seconds, you can agitate every minute or even more. Again I can't remember the exact science, but increased agitation leads to denser negs, which can be harder to print for a full tonal range. Of course; you might want very contrast pictures. You could use a stronger solution, and increase the water temp. There are no real 'rules'. It's fun to experiment.
