ISO 11421:2025

This International Standard provides general guidance on the evaluation of error sources in optical transfer function equipment and the use of this information to estimate OTIF measurement errors. It also gives guidance on the assessment and specification of a general accuracy pattern of specific measuring equipment, as well as methods for recommending routine evaluation. The main body of this International Standard deals exclusively with of the modulation transfer function (MTF) part of the OTF. The phase transfer function (PTF) is covered quite briefly in Appendix A.
(Automatic translation from French)