Last week we talked about Image Stabilization, also variously referred to as Vibration Reduction, Anti-Shake and Anti-Blur. This week let’s look at a different feature that is often confused with Image Stabilization. Its name may sometimes sound similar but its function is completely different.

This menu option, which is available only on SLR cameras, may variously be called Anti-Shock, Mirror-Lockup or some other such thing. The terminology depends on the manufacturer but the functionality is universal.

When turned on, Anti-Shock delays the shutter opening for some preset time (usually 2-5 seconds) after the shutter button is pressed.

Why would you want to introduce a lag time between when you press the button and when the picture is actually taken?

With SLR cameras, there is a mirror which sits between the lens and the “film plane”. You can see it when you remove the lens and look into the camera body through the flange. This mirror is hinged on most cameras (a few models have been tried over the years which use translucent mirrors that remain in place.) The mirror swings up out of the way while the exposure is being made.

The Anti-Shock delay is to allow vibrations from the mirror movement to dampen before the exposure is made. While this function is not useful for any kind of action shots, it can be very useful for landscape photos, macros and other cases where the subject is not moving and you want maximum sharpness.

Anti-shock is not available on point-and-shoot, rangefinder or other types of cameras without a mirror. And although it can be used at any time, anti-shock is only effective when the camera is on a tripod or other support.

One final thing to watch out for is that Anti-Shock is usually not self-resetting. Once you turn it on it remains on until you turn it off again. If you forget, you may find yourself trying to grab an action shot only to miss it because of a delay you weren’t counting on.

Want to learn more about your camera’s advanced features?