What Film I Use
Fuji Pro 400H:
I "borrowed" a roll of this from my wife when I tried the Lubitel and, while the Lubitel didn't really produce great pictures, the film was undoubtedly the finest I've ever seen at that speed. In medium format, at reasonable enlargements it's almost grainless to the naked eye, and even enlarged to 12" square, it's pretty difficult to see the grain. A perfect combination of speed, colour rendering and fine grain. And an utter shame they discontinued it (which is why half of my freezer is filled with it).
Fuji Provia 400X/F:
In medium format, even 10 years expired, this reversal film is superb at rendering nice, balanced, realistic colours at a high speed. Like the Pro 400H, the grain is so fine as to be indistinguishable unless projected really large, and in scans/enlargement prints, similarly lacking in grain. A real beauty of a film and another crying shame that it's been discontinued for so long. I haven't tried Provia 100F pushed to 400 but I have heard that it stands up well; while I still have rolls of 400X in the freezer, I'll stick to that!
Fuji Neopan Acros II 100:
Supremely high quality, incredible resolution, punchy contrast and exquisite latitude; I usually shoot at 400 and push 2 when getting it processed. Even that doesn't reveal much grain, that's how extremely fine grained this film is.
Kodak Ektachrome 100:
Good saturation, but a little cool for a lot of applications for my liking. It's a great counterfoil to Velvia 100, with the Velvia rendering a touch warmer.
Fuji Neopan 400CN:
One of my two go-to B&W films for 35mm - a good combination of speed, grain and ease of lab processing.
Kodak Ektar 100:
A little too saturated for everyday use but a lovely 100 speed colour negative film.