iso on film

cypilk · Apr 25, 2004

what does this mean for film?

Excellent Push/Pull Processing capability to ISO 1600

cypilk · Apr 25, 2004

more like..what am i looking for when i buy a roll of film?

markc · Apr 25, 2004

That means that you can override the camera and tell it to expose the film as if it were 1600 speed and then develop it as if it were. It's usually better just to by faster film, but if you like T-Max, for example, you have a choice of 400 or 3200, not 800 or 1600. You could push the 400 to 1600, or pull the 3200 to 1600.

It's usually best to go with the slowest speed film that will give you the shutter/aperture combo you want to use, as this will minimize grain. Pushing will increase grain, though. If you don't need to push or pull, you don't have to worry about how far the film will go.

cypilk · Apr 25, 2004

do you mean override the film?..cause when i put a new roll of film in..i have to program the iso number into my camera.... so.. if i put in 400 film ...do u mean i can push the film to 1600 by programming the camera to 1600?

markc · Apr 25, 2004

cypilk said:
do you mean override the film?..cause when i put a new roll of film in..i have to program the iso number into my camera.... so.. if i put in 400 film ...do u mean i can push the film to 1600 by programming the camera to 1600?

Yup. But the roll needs to be developed as if it were 1600. Most one-hour labs won't do that, so you need to find out what the times are and do it yourself, or bring it to a pro lab. They usually charge extra.

As an example, this shot was taken on T-Max 3200 pushed to 6400. Even then (and with an aperture of f1.8 ), the shutter was still slow enough to get motion blur.

cypilk · Apr 26, 2004

so..how do you PUSH a film.... whats the difference in developing a 3200 film as a 6400 .. is there a different technique in developing?

ksmattfish · Apr 26, 2004

If you increase a film's speed you are intentionally under-exposing it. You will then compensate for this under-exposure with over-development (increasing the time it's in the developer). Of course there are practical limits to how much a film can be pushed, and some push better or farther than others.

If you are developing your own film at home there are instructions about the time increase in the literature or on the companies' websites.

If you are taking your film to a lab be sure you discuss this with them before you shoot to determine how they can help you. For instance, most pro labs can push a stop or two, most mini-labs won't know what you are talking about, and some labs can push more than two stops.