CNS 7475-1981
Methods of Measurement for Effective Aperture, F - number, Aperture Ratio and T-number of Photographlc Lenses (English Version)

Standard No.

CNS 7475-1981

Language

Chinese, Available in English version

Release Date

1981

Published By

Taiwan Provincial Standard of the People's Republic of China

Latest

CNS 7475-1981

Scope

This standard specifies the measurement methods for effective aperture, F number, aperture ratio and T number of photographic lenses (hereinafter referred to as lenses) that comply with CNS 6293 General Principles for Determination of Focal Length of Photographic Lenses.

CNS 7475-1981 history

• 1981 CNS 7475-1981 Methods of Measurement for Effective Aperture, F - number, Aperture Ratio and T-number of Photographlc Lenses