A camera's shutter is one of the two mechanisms that control a key aspect of exposure by determining how long the sensor is exposed to light to record the image. In the early days of photo-imaging, all shutters were mechanical. There were two types: leaf shutters and focal-plane shutters.
Leaf shutters consist of a set of overlapping blades (or ‘leaves’) that open by moving outwards when the shutter is engaged and remain open for a set time. They’re used mainly in fixed-lens cameras and some lenses, where they are located between lens elements near the iris diaphragm blades that control the aperture diameter. This design minimises vignetting
