High Spatial Frequency MTF Measurement Measurement Scheme
Original Publication Date: 1983-Mar-01
Included in the Prior Art Database: 2005-Feb-06
A method is described for measuring the modulation transfer function (MTF) of an optical system at a spatial period which is less than the resolution of the measuring device to be used. Two grating images are formed having a spatial period less than the resolution of the measuring device, at least one of the grating images being formed with the optical system to be measured. Then a Moire pattern is formed from the two grating images, the Moire pattern having a spatial period which is greater than the resolution of the measuring device. The MTF of the Moire pattern is then measured, and the MTF of the optical system is derived therefrom.