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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