Interlaboratory Comparisons of MTF Measurements and Calculations and OTF Standards in Germany

Abstract

The Committee on Quality Assessment of Optical Systems, group of the German Standards Institution (DIN) is engaged in the standardization of OTF measurement technique. The state-of-the-art of MTF measurements and calculations shows an agreement of a few percent. This is the result of MTF measurements and calculations performed on two lenses by several laboratories in Germany and in England. Lens No. 1: f/3.2, f = 100 mm, infinite conjugate, angular field up to 12.9°, A = 546 nm, spatial frequencies up to 400 c/mm. Lens No. 2: f/5.6, f = 90 mm, infinite conjugate, angular field up to 45.1°, A = 546 nm, spatial frequencies up to 80 c/mm. The agreement obtained encourages MTF standardization and the use of MTF to describe the optical quality of image-form-ing systems. A report on the results of the committee's work is given. The work is divided into four parts: Sheet 1. Symbols, Definition, Mathematical Relations Sheet 2. Equipment Parameters Sheet 3. Practical Measurement Sheet 4. Evaluation and Representation of Measurement Results.