Several of the cameras that we use a lot do not have fast plastic or glass, i.e. the apertures do not open sufficiently for low-light photography. That is where high speed films like the Fuji PRO 800Z come in!
I really love high speed film. It allows me to shoot in bad light with many of my cameras which do not allow for low-light photography under other circumstances. One of the films I particularly like is Fuji PRO 800Z, especially for portraits, as it has a really natural skin tone rendition. Unfortunately, this film has been discontinued by Fuji last year, so if you want to try some, get going while there is still some of it left!
I had bought several expired batches of the film and must say that I was very lucky as the film was still at nominal sensitivity despite expiry. This is a professional film, so it should actually be refrigerated to maintain optimal saturation. For me as a lomographer, that is not always important. The film is very sharp and has a good exposure latitude, especially compressing well the highlights when overexposed (which can be a danger when shooting it under changing circumstances, like on a lomowalk).
When expired, it does not handle underexposure very well, answering with a colour cast, but hey, who said that’s a bad thing, right?