Archived posting to the Leica Users Group, 1999/07/27
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]"Noel H. Charchuk" wrote: > Alex asked: > What does the 'f' in f-stop stand for? ><snip> > According to the Ilford Manual of Photography, relative aperture is the > relationship of the focal length of the lens divided by the diameter of > the effective aperture. N=f/d. "The numerical value of relative aperture > is usually prefixed by the letter f and an oblique stroke, eg f/8. The > letter f and the stroke serve as a reminder of the relation between > relative aperture, effective aperture and focal length. The relative > aperture of a lens is commonly referred to as its f-number" ><snip> In other words: you don't know! Mark :-) Rabiner