The most important reason to use film is the fact that you don't have immediate feedback like with DSLRs. This is an important learning process, IMHO, for it forces the photographer to think before actually making the exposure, instead of shooting and looking at the histogram to find potential errors. That's the best school for becoming a better photographer, at least technically.
You have to use transparencies slide film for that, though, because color negative allows for too much margin when it comes to exposure errors, thanks to an excellent dynamic range (8 to 12 stops!), while slide film has about 5 stops of DR, a little less than most modern APS-C DSLR (8-9 in lab 7-8 in real world shooing, with about 1 stop more in RAW).
On top of their respecive DR, negative color film also as an exposure error margin of about -3 EV to +2 EV, while a transparency slide film has an exposure error margin of about -1 EV to -0.5 EV.
Because of the less forgiving nature of slide film, your exposure as to be spot on, otherwise you'll get underexposed or overexposed pictures with highlights or shadows that are near impossible to recover.
B&W negative film usually has less DR than color negative, but more than slide film, with similar results on the exposure margin error they allow.
This is especially true for ultrafine grain film (Kodak T-MAX, Ilford Delta), which requires more accurate exposure than older film (like Kodak Tri-X Pan) with coarser grain, which are usually more tolerant of exposure errors.
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Out of the learning process, the increased DR of color negative film over digital sensors might be another reason to use film instead of shooting with DSLRs. But with HDR imaging, the advantage is to DSLR for static subjects.
Also, B&W film, when carefully processed, can also show more subtle gradients in the shades of gray than most DSLRs do, even when processed from RAW files.
You can also get very interesing results using specialized films (Fuji Velvia, with its vivid but natural colors) or techniques (cross-process, bleach bypass), but most of these results can be mimicked in post-processing (DxO film pack and Silver FX are great software for that).
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Other than that, DSLRs beat film SLRs hands down IMHO: much more sharpness, more accurate colors (well, usually), much, much better low light performance and an unbeatable flexibility, including the possibility to change ISO at will.
There's one last reason to use film: the magic of using old cameras and developping pictures yourself. People might be nostalgic or not, but the sound of an old film SLR is truly unique, as is the feeling of its metal body and using its simple commands. Then, seeing your B&W image slowly coming to life in a developper bath is another unique moment DSLR can't offer. But quite frankly, I'll pass on the chemistry odors... it just stinks!!! By comparaison, my CaptureOne RAW developper doesn't smell anything! :lol:
Haven't touched a film camera in 5 years... I need to shoot film soon, if I don't want to loose the "craft"!
Still shopping for a Mamya 645 AFD, so I can fit in a (rental) digital back when needed. These machines are a bit too expensive for my wallet right now.
