09
INSTRUMENTS FOR THE MEASUREMENT OF
PHOTOMETRIC CHARACTERISTICS OF AERIAL SURVEY CAMERAS
Y. Chiba
Japan Camera and Opt. Inst. Inspection and Testing Institute
Tokyo, Japan
K. Sayanagi and S. Koyanagi
Canon Inc.
Tokyo, Japan
K. Iwai and T. Habuchi
Geographical Survey Institute
Tokyo, Japan
ABSTRACT
Two instruments for the measurement of photometric characteristics of
aerial survey cameras are described.
One instrument is for the measurement of the exposure distribution
over the film plane of the cameras. The other is for the measurement
of the colored (usually blue) glare spot which appears at the center
of a picture.
Measurement principles and results for the various cameras are dis-
cussed.
i. introduction
Out of several photometric characteristics of aerial survey cameras,
we have studied two over the past two years by constructing measuring
instruments and investigating measured results.
One of these characteristics is the exposure distribution over the
film plane, and this distribution varies from one camera to another
due to the cos^0 law, lens vignetting and anti-vignetting filters (A.
9. filter).
Ui
ince the exposure distribution is very important for color photo-
raphy. We have chosen this characteristic for our photometric stud-
es
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