WAVEFRONT DISTORTION

Precision-Optical Engineering has added IF007, “Wavefront Distortion Measurement — MTF vs. Interferometry,” to its series of downloadable data sheets about interferometry. The two-page document compares two methods of measuring modulation transfer function (MTF) in optical components and systems: Fourier transform of measured line-spread function and interferometric measurements. It explains MTF and how it provides a quantitative measure of image quality. The benefits of both techniques in the design of zoom optical telescopes are presented as a practical example.