Focal ratio synonyms
The ratio of the focal length of a lens or lens system to the effective diameter of its aperture.
the ratio of the focal length to the diameter of a (camera) lens system
Speed is a slang term for the street drug methamphetamine.
Find another word for focal ratio. In this page you can discover 3 synonyms, antonyms, idiomatic expressions, and related words for focal ratio, like: f-number, stop number and speed.