If you were to take 10 images on 50 speed film, for example, and then needed to use fast film, 800 speed for instance - could you unwind the partially used roll of 50 speed and then put it back in at a later point?
Just curious about this. I read that you could, but I can't figure out how you would know when to stop winding, so as not to wind the film entirely into the roll, thus rendering the whole thing useless.
I use a Nikon FE2.
Yes you can. Take a note of the frame counter and write down what number it's on. When rewinding listen and feel for it coming off the take-up spool and then stop rewinding. But even if the leader goes back into the cassette, you can extract it with a leader extractor. When putting it back, put a lens cap on the camera and wind on and shoot to a couple of frames past where you took it out.