Shutter

The shutter of a camera or of the lens/shutter unit for a camera isolates the film in the camera from light until the shutter will be released. Depending on the shutter type releasing the shutter means to open it for a moment like a diaphragm, like a roller blind, or simply like a sliding door. A wind-up-mechanism or a litte electric servo delivers the shutter movement energy and controls the time of film enlightening.

focal plane shutter

Focal plane shutter means that the shutter is located near the film plane. Most focal plane shutters are of the roller blind type, as light-tight roller blind over the rectangled window over the film plane, with a second roller blind closing the shutter window immediately when the other blind is opened or just opening. Fast shutter speeds are achieved by letting the light in through a narrow gap between the opening and the closing roller blind.

leaf shutter

In some cameras the diaphragm of the leaf shutter and the diaphragm that defines the aperture for the exposure are identical. But in most cases there are two diapragms behind a camera lens or between its optical elements. Then the shutter has less but faster leaves. Fast speeds can be achieved by limiting the aperture range for the fast speeds to small and that of the slow speeds to larger apertures.

guillotine shutter

Imagine a sliding door opening and shutting. Sometimes such simple shutter constructions are called guillotine shutters.

Glossary Terms