Knowledge Gateway
Unlock your learning potential with industry insights and standards that matter. Share your email to begin.
Unlock your learning potential with industry insights and standards that matter. Share your email to begin.
Status : Active
Standard Type : Main
Document No : ISO 517:2008
Document Year : 2008
Pages : 8
Edition : 3
Section Volume : Fundamental standards (ISO/TC 172/SC 1.)
ISO 517:2008 specifies aperture markings for all types of lenses used in still cameras, and gives tolerances for the stop numbers. It also defines aperture stop, entrance pupil, focal length, relative aperture and stop numbers, and gives methods for their measurement or determination.
ISO 517:2008 applies only to lenses focused on objects at infinity; that is, at least 50 times the focal length of the lens.