shutter button
In photography the shutter-release button (sometimes just shutter release or shutter button) is a push-button found on many cameras, used to take a picture. When pressed, the shutter of the camera is “released”, so that it opens to capture a picture, and then closes, allowing an exposure time as determined by the shutter speed setting (which may be automatic). Some cameras also utilize an electronic shutter, as opposed to a mechanical shutter. The shutter-release button is one of the most basic features of a handheld camera. Camera phones that lack a physical button for this purpose use a virtual button on the virtual keyboard. The term “release” comes from old mechanical shutters that were “cocked” or “tensioned” by one lever, and then “released” by another. In modern-day photography, this notion is less meaningful, so is gradually falling from use.
