DIN ISO 9335:2015-12

The optical transfer function is an important aid to objective evaluation of the image-forming capability of optical, electro-optical and photographic systems. Different measurement principles are used to measure the OTF. In order to obtain comparable measurements of OTF from measuring instruments in different laboratories, it is necessary to ensure equivalence of measurement parameters such as focus setting and spatial frequency range. For this reason, an agreed terminology has been defined in order for the measurement parameters used in this standard to be understood by all users. This standard specifies important factors that can influence the measurement of the OTF, and gives general rules for equipment performance requirements and environmental controls. It specifies important precautions that should be taken to ensure accurate measurements and correction factors to be applied to the collected data. The OTF measuring equipment described in this standard is restricted to that which analyses the radiation distribution in the image plane of the optical imaging system under test. Interferometer-based instruments are outside the scope of this standard. The committee responsible for this standard is NA 027-01-02-01 AK "Messverfahren für die Optik" ("General optical test methods") at DIN.