The Brightness Science Your Machine Light Spec Sheet Hides

A supplier sends a spec sheet: 5,000 lumens, 6500K, IP67, 60W. It looks perfect. Then you mount it, fire it up, and the beam lands like a floodlight at a sports event — everywhere except the part.

Here is what the numbers actually mean, and which one to look at first when you buy your next LED machine work light.