Commission I 1
Recommended Procedures for Calibrating Photogrammetric
Cameras and for Related Optical Tests
Collated by P. D. CARMAN
Revision of September, 1960
Note: A recommendation on procedures to be used in calibrating photographic cameras
and in related optical tests was adopted by the VIIth International Congress of Photogram-
metry in September 1952 for trial and discussion. Subsequent experience has led to some
revision of the earlier recommendations. The current revised recommendations, as approved
by the IXth International Congress of Photogrammetry in plenary session in September
1960, are printed below.
PREAMBLE
Calibration and testing techniques for photogrammetric cameras have undergone
considerable development in recent years. The developments in the various countries con-
cerned have not been co-ordinated and as a result a great variety of test procedures has
arisen. The users of photogrammetric cameras may be unfamiliar with the procedures used
by the various testing agencies and so may have difficulty in using their reports, since the
numerical values of the various properties of the cameras are very dependent on the man-
ner in which they are measured. It is clearly desirable that a single reliable test procedure
should be agreed upon and used for testing all complete photogrammetric cameras in order
that users of the cameras may accept their calibration with confidence and in order to
permit direct comparison between reports from various testing agencies throughout the
world. This test procedure should produce results which are in agreement with practical
use yet should be simple and quick to use. Consequently test methods should resemble
practical use closely enough to ensure freedom from systematic differences yet should avoid
practical conditions causing random errors which would have to be reduced statistically
by making large numbers of observations. For example air turbulence, vibration, uncer-
tainties in camera temperature, and random irregularities in emulsion surface are best
avoided. It is the purpose of this present recommendation to approach as closely to this
single test procedure as is currently practicable. To facilitate consideration and adoption
of the recommendation, it has been kept as short and as simple as is consistent with
adequate exactitude and the subjects covered have been limited to calibration, resolution,
image illumination, veiling glare, and deviations of filters and port glasses.
Considerable variations in test procedures have been permitted within the scope of
the recommendation. These variations are certainly undesirable. However, it must be
remembered that this international recommendation necessarily represents a compromise
between various well-established national test procedures. This recommendation is not
intended to restrict improvements in calibration techniques or changes necessitated by new
camera types. When changes are found to be desirable they should be reported promptly
to the Chairman of Commission I.
This recommendation contains definitions of photogrammetric terms to the extent that
such definitions are required by the purpose of the recommendation. Since only the testing
of real cameras is dealt with, these definitions are entirely technological in form. They do
not deal with the mathematical simplifications of photogrammetry nor with the imaginary
concept of a perfectly made camera without manufacturing errors. They define the major
properties of a real camera in the presence of unavoidable manufacturing inaccuracies
and give unambiguous names to the errors produced by these inaccuracies.
This recommendation has been prepared on the assumption that tests will be carried
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