Flash synchronization

In <a href="/facts/Photography/ezLPT43M">photography</a>, flash synchronization or flash sync is the synchronizing the firing of a <a href="/facts/Flash_(photography)/bfegk3Xy">photographic flash</a> with the opening of the <a href="/facts/Shutter_(photography)/83Y5rsB0">shutter</a> admitting light to <a href="/facts/Photographic_film/37aFq6ls">photographic film</a> or electronic <a href="/facts/Image_sensor/j3GNrRln">image sensor</a>.

In <a href="/facts/Camera/j4uqsfJQ">cameras</a> with mechanical (<a href="/facts/Clockwork/ofYRa6kD">clockwork</a>) shutters synchronization is supported by an <a href="/facts/Electrical_contact/eELyUxrd">electrical contact</a> within the shutter mechanism, which closes the circuit at the appropriate moment in the shutter opening process. In electronic <a href="/facts/Digital_camera/LSGTserm">digital cameras</a>, the mechanism is usually a programmable electronic timing circuit, which may, in some cameras, take input from a mechanical shutter contact. The flash is connected electrically to the camera either by a cable with a standardized coaxial <a href="/facts/Prontor-Compur/V02yY0ts">PC</a> (for Prontor/Compur) 3.5 mm (1⁄8 in) connector (as defined in ISO 519), or via contacts in an accessory mount (<a href="/facts/Hot_shoe/3WYePXfc">hot shoe</a>) bracket.
Faster shutter speeds are often better when there is significant ambient illumination, and flash is used to <a href="/facts/Flash_fill/gfEMVY7r">flash fill</a> subjects that are backlit without <a href="/facts/Motion_blur/y7jR2shk">motion blur</a>, or to increase <a href="/facts/Depth_of_field/xWo3J8b0">depth of field</a> by using a small <a href="/facts/Aperture/8PV11GQm">aperture</a>. In another creative use, the photographer of a moving subject may deliberately combine a slow shutter speed with flash exposure in order to record motion blur of the ambient-lit regions of the image superimposed on the flash-lit regions.

Flash synchronization open-in-new

Flash synchronization