Self timer

A Self timer is a device on a camera that, when enabled, gives a delay between the pressing of the shutter release and the shutter firing. It is most commonly used to allow photographers to take a photo of themselves, hence the name.

However, the self-timer mode is also often used to reduce camera shake when taking photographs in low light or with long telephoto lenses. The action of pressing the shutter release button shakes the camera to some degree. If the self-timer is used, the delay before the shutter fires allows the camera to be held more securely, or to sit without vibration on a tripod or other support.

Most cameras with a self-timer function flash a light or LED during the countdown, emit a beeping sound, or both. These warnings generally increase in speed or intensity as the count reaches the last few seconds, to alert that the shutter is about to fire.

The most common delay provided with a self-timer function is 10 seconds. Some cameras also give a 2 second setting, or an adjustable setting. Very few cameras can be set up to fire at a specified time.

Single-lens reflex cameras have to flip up the viewing mirror before the picture is taken, which can also shake the camera. It is not uncommon for a camera to combine mirror lockup with the 2-second self-timer mode, which is generally used to reduce camera shake still further.

Alternatives to the use of the self-timer function include forms of remote shutter release, including a cable release, an infrared remote control, or other means.