I believe there's another element at work that kevs is not recognizing: to the amateur market, fast box speed sells better than slow box speed. So the film manufacturers will come up with an emulsion that may be pushing the envelope a bit to shoot at rated speed, whereas if you bump it down a notch or two, it allows the emulsion to perform better. I cite Fuji Superia 400 as an example. My results with shooting Superia 400 at box speed have been simply dreadful. Clumping of grain, splotchy color, just all in all a very bad film, in my view. I can't blame the camera, which has an electronically timed shutter and which stops down the lenses accurately. And I can't blame the developing lab for it either, since they do an excellent job on other C41 emulsions I give them to process. But if I shoot Superia at 320, it becomes a totally different animal. Grain has smoothed out, colors are richer, all in all not a bad film at all.
Now, while it's true that films like Portra are not considered to be amateur films, I think nonetheless that the mindset pervades.
Last edited by cooltouch; 05-09-2013 at 08:17 AM. Click to view previous post history.