ISO 9336-3:2020 pdf download

ISO 9336-3:2020 pdf download

ISO 9336-3:2020 pdf download.Optics and photonics — Optical transfer function — Application
1 Scope
This document specifies a method of testing telescopes in terms of imaging states aimed at making valid optical transfer function (OTF) measurements.
This document includes two annexes (Annex A and B) that provide information on the more recent
techniques for measuring optical transfer function and methods of deriving image quality criteria from such measurements.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 9334, Optics and photonics — Optical transfer function — Definitions and mathematical relationships
ISO 9335, Optics and photonics — Optical transfer function — Principles and procedures of measurement
ISO 14132-1, Optics and photonics — Vocabulary for telescopic systems — Part 1: General terms and alphabetical indexes of terms in ISO 14132
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 9334 and ISO 14132-1 apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
4 General description of test specimen types and the relevance of OTF tests
The specimens considered are telescopic observational instruments with direct view used for viewing remote objects and include many instruments such as telescopes, binoculars, telescopic sights or spotting scopes. Ideally, instruments would be best with no astigmatism and no field curvature coupled with good chromatic correction but frequently compromises as mentioned above shall be tolerated. Many optical systems include roof prisms to give a compact instrument. However, the image produced by such systems is basically made up of two superimposed images and the accuracy with which they match will depend on the accuracy with which the roof edge has been constructed. In such cases the orientation of the roof edge shall be noted (see 5.5).
In use, the eye is coherently coupled to the telescope, so it may be contended that the only valid test would be one that included the eye: reference is made to the case of cascaded optical systems in the introduction to ISO 9334. However, in observer tests using telescopes, improved performance has been obtained with instruments with better measured OTF performance in a variety of tests, including contrast sensitivity using sinusoidal grating targets, which confirms the value of OTF tests. OTF tests also enable performance to be compared with that computed by the telescope designer and provide effective quality assurance tests of production specimens.