Instruments for the Measurement of Photometric 
Characteristics of Aerial Survey Cameras 
K. Sayanagi Canon. inc., Tokyo 
Y. Chiba Japan Camera and Optical Insturments Inspection 
and Testing Institute, Tokyo 
K. Iwai and T. Habuchi 
Geographical Survey Institute, Tokyo 
ABSTRACT 
Two instruments for the photoelectric measurement of photometric 
characteristics of aerial survey cameras are described. 
One is for the measurement of the exposure distribution over the 
focal-plane of the camera. The instrument is also able to measure 
the illuminance distribution and the effective exposure time. The 
measurements are made by 15 silicon photocells located along a 
diagonal of the camera picture format. 
The other instrument is for the measurement of the colored (usually 
blue) glare spot appearing at the center of the picture. The 
extended light source of the instrument is set on the focal-plane 
of the camera being tested. The small light receptor located at 
the center of the extended light source detects the reflecting 
light flux from the lens surfaces. The light receptor is capable 
of selecting 3 spectral bandwidths, blue, green or red. 
The measurement principles and the results for various aerial 
survey cameras will be discussed.