The f-stop of an optical system expresses the diameter of the entrance pupil in terms of the focal length of the lens; in simpler terms, the f-stop is the focal length divided by the "effective" aperture diameter. It is a dimensionless number that is a quantitative measure of lens speed, an ...
How many stops can a digital camera capture? Additionally, does anybody know what the dynamic range is for negative and positive film, the human eye, computer monitor, the television, etc...
What does f-stop mean? Is it the same thing when people say "2 stops" for example?