40 ABSOLUTE BEGINNER’S GUIDE TODIGITAL PHOTOGRAPHY
FIGURE 3.5
Low-light photo
taken with ISO
1600-speed film.FIGURE 3.6
Film with an
ISO rating of
100–400 is usu-
ally fast enough
for most out-
door photo-
graphy.If light is moderately bright, a film of medium speed still lets you use a relatively
fast shutter speed, so you can hand-hold the camera or record moving objects
sharply. The slowest film speeds would require a tripod to hold the camera steady
during a longer exposure of the same scene. Medium-speed films are also useful if
you want to maximize the depth of field by using a small aperture, which is not
always feasible with a very slow film.