And you'll get more natural-looking outdoor shots. Fill-in flash is especially effective with pictures of people. It's really very easy to get professional-looking shots. Just turn on the fill-in flash and your camera will make the necessary computations automatically. This is usually a big mistake.
Color film is balanced for use with either daylight or flash.
Shooting without a flash will result in yellowish pictures under incandescent lighting or greenish photos if taken under fluorescent light. One of the most common mistakes people make is to use a shutter speed that is higher than their camera's flash synchronization speed. This results in part of the image being blacked out by the focal plane shutter. The maximum sync speed your camera can handle will probably be shown on the camera's shutter speed indicator. Any slower speed may be used.