I have recently started getting into film photography and I’m still learning the ropes. After buying a variety of color and black and white films to experiment with, I noticed that I somehow accidentally bought a couple of rolls of very high speed Ilford Delta ISO 3200 film. At this point, all I have is a Kodak Ektar H35N and an Olympus Pen-EES 2 which has a max ISO of 400. Is the Ilford film useless to me, or can it be used at lower speeds in certain conditions?
Beware long exposure times. Rated ISO will drop (sometimes drastically) for exposures longer than 1 s.