Choosing the right film speed can make a difference in print quality, so it's important to try to match up ISO numbers with the nature of your subject. Some professional photographers carry around two or three cameras loaded with different film or speeds, but clearly, this is impractical for most amateur shutterbugs.
- 100 ISO. If you are mostly shooting non-moving outdoor subjects in daylight, such as landscapes and scenery, 100-speed film is your best bet. This speed also works well for indoor shots with a flash.
- 200 ISO. For occasional photographers and general-purpose use, 200-speed film is a good default choice. This film produces good outdoor photos in both sunny and cloudy daytime conditions, as well as indoor flash shots. 200-speed film, like 100-speed film, is best for subjects that don't move around much. You'll need a faster ISO if you want to capture moving subjects.
- 400 ISO. Faster speeds like 400 and 800 ISO are best for moving subjects, like wildlife and sports. With the faster speed comes less definition. Faster film-speeds also produce better low-light photos.
- Other speeds. You can find film up to 1600-speed, but unless the subject is a 200-mph Nascar race, most people won't need a film this fast.
Also keep in mind that an enlargement beyond an 8x10 print can turn out blurry if you've used a high-speed film, since you can lose detail due to stretched grain. If you're hoping to blow up a print for a poster or other larger format, go with 100-speed film. For other speeds, enlargements will look better in sizes under 8 x 10 inches.
It isn't absolutely necessary to store unexposed film in the refrigerator, but do keep it in a cool, dry place. And while it's cheaper to buy film in larger quantities, it does have a shelf life. Don't buy so much film that you end up with expired film; you risk poor prints by using film after the expiration date on the box.