# Shutter lag > The delay between triggering a camera and the moment the image is actually exposed. Also known as: trigger advance. Category: Photography techniques. Shutter lag is the delay between the trigger signal and the moment the camera actually exposes the image. It varies between camera models and matters whenever the subject is moving, because the subject keeps moving during the delay. ## How PhotoRobot uses it In non-stop capture the PhotoRobot control unit fires the camera in advance of each target angle. The "Trigger advance" value must be higher than the camera's shutter lag; PhotoRobot's example is about 90 ms for a camera with an 80 ms lag. With several cameras, the [SynchroBox](https://www.photorobot.com/glossary/synchrobox) applies each camera's own lag, and the SynchroBox guide explains how to measure it. ## See on photorobot.com - [SynchroBox: how to measure shutter lag](https://www.photorobot.com/manuals/synchrobox-setup) ## Related terms - [Fast Spin](https://www.photorobot.com/glossary/fast-spin): PhotoRobot capture mode that photographs during continuous turntable rotation instead of stopping at each angle. - [SynchroBox](https://www.photorobot.com/glossary/synchrobox): PhotoRobot multi-camera controller that fires each camera with its own advance; up to 8 cameras per unit, units can be linked. - [Shutter release cable](https://www.photorobot.com/glossary/shutter-release-cable): A cable that fires the camera from an external device, such as a robot's control unit. - [Shutter speed](https://www.photorobot.com/glossary/shutter-speed): How long the camera shutter stays open; with flash, the flash duration usually freezes the motion instead. ## Where this term appears on photorobot.com Mentioned on 1 page. Most relevant: - [PhotoRobot SynchroBox - Functionality & Setup User Guide](https://www.photorobot.com/manuals/synchrobox-setup): It represents a solution to the issue that arises when working with cameras that have different shutter lags, and one unit supports up to 8 cameras.