title: MTF measurement of TV zoom lenses: influence of distortion on the equivalence of normal and inverse conjugate techniques.
abstract: Influence of distortion is studied with regard to the equivalence of the normal and inverse conjugate techniques used in the measurement of MTFs of TV zoom lenses. The two techniques can be regarded as practically equivalent only when the local magnification (as distinguished from the conventional paraxial magnification) is utilized in frequency conversion needed in the inverse conjugate technique. A sample TV zoom lens is presented as a numerical example which supports the results of the discussion. A simple method is proposed for determining the local magnification simultaneously in the process of the MTF measurement.
authors.forename: M
authors.initials: M
authors.lastname: Takeda
authors.forename: K
authors.initials: K
authors.lastname: Takesi