Radiometry Simplified

Specifications and measurements of light often seem more confusing than they really are. Most common specifications for light fall into one of four geometries and one of three spectral descriptions, describing twelve distinct cells. These are shown on this chart. The vast majority of light measurements fall into one of these boxes. Radiometry is a lot simpler if you know which of the twelve boxes you’re working in, (and when you’re not in any of them).