There's a multitude of emulsions available, even after a lot of them have been discontinued. Each one reacts a little differently to light, both in terms of requiring more or less light, but also in terms of reacting in various unique ways to light.
I've been spending a lot of time in the past year or so on finding ways to continue to shoot film, but doing it more economically. The first step was getting my own scanner so I didn't need to pay somebody to print or scan my photos. Lately, I decided that my cost of B&W developing was too high, so I set up my own darkroom