A focus light is a broad beam of light designed to help a photographer create a sharp image by adding contrast to a subject. However, a focus light can also help a photographer keep an eye on a small or camouflaged subject; it may serve as a primary source of illumination during a night dive; it might also serve as a prop during an underwater photo shoot.
On Backscatter, Brad Brown has written the mother of all focus light overviews, carefully covering what to look for if you’re in the market for a new focus light. Then, Brown puts 6 focus lights through the grinder, comparing their beam qualities, sizes, weights, battery lives, and painstakingly identifying their pros and cons.
If you thought your light was “good enough,” you’ll whistle a different tune after reading his report.