Handheld Light Meter
A separate instrument for measuring incident, reflected or flash light independently of the camera.
Measured in
EV, f-stops
In depth
A handheld meter is the only practical way to measure studio flash before firing a frame, and the only way to take a true incident reading. Modern units combine ambient and flash modes, can measure the ratio between the two, and offer a one-degree spot for reflected readings. Film photographers rely on them absolutely, since there is no histogram to check.
Examples in practice
Setting up a three-light portrait: key metered at f/8, fill at f/5.6, rim at f/11, all confirmed before the model arrives.