Lens opening/aperture/f-stop (these numbers are the bottom half of a fraction) Longer exposure means more motion blur Shorter exposure gives less blur, stops action Longer exposure let in more light Shorter exposure lets in less light Higher numbers look grainier or noisier, but you don’t need as much light. Lower numbers give sharper photos with better color.
ISO – the sensitivity of the camera’s sensor or film to light. In most cases the photo booth software overrides the physical buttons and dials on your camera. However, the other three variables are under your control.
If you do use a flash (sometimes called a strobe) you’ll want some continuous light so the camera can see to focus and so the guests can see what they’re going to look like. If you don’t use a flash unit, this is the only light that makes an exposure.
If you’ve gotten into the photo booth business without spending too much time as an old-school photographer, you might find this basic guide to exposure handy.
