Details of data on the two reaseu camera used in the compara-
tive tests for the Image Geometry WG and OTF/MTF WG of Commission
I will be discussed at the Congress.
Routine tests of MTF and resolution are now being made on
aerial cameras both in the laboratory and in flight. The same
goniometer and test field also provide calibration elements for
photogrammetric cameras.
5.6 West Germany :
5.6.1 OTF Standards Activity. The Physikalisch-Technische
Bundesanstalt (PTB), began to develop photo-electric instruments Q
to measure the OTF of photographic camera lenses in 1954. The committee
for standards requested OTF measurements be conducted to investigate
the replacement of quality specifications for resolving power.
The standard which was planned to be introduced was delayed until
1970 due to lack of measuring equipment, particularly with the smaller
manufacturers, although OTF testing was in common use prior to that
date for phototypes and for limited production.
The DIN 58185 standard comprises five sections.
l. Formula symbols, terms, mathematical relations
2. Fundamentals of instrumentation
3. Performing the measurement
4. Evaluation and presentation of results
5. Criteria for quality evaluation by means of the OTF 9
In Section 1, OTF terms are defined; assumptions and restrictions
are stated for the strict mathematical validity of the relations
listed. Methods of calculating the OTF from the wave aberration
by means of the auto-correlation integral or from the point spread
function, the line spread function, and the edge spread function
are also given.
Section 2 presents guidelines for designing instruments for
measuring the OTF imaging systems and conditions regarding test
sites are listed. The standard applies to any imaging system which
obeys the law of practical isoplanasy, whose illumination is spacially
incoherent and which yields linear imaging. Individual paragraphs
state requirements and data processing system. No specific instru-
ments or designs are cited.
