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Regarding astigmatism, the ordinary camera lens has the value of 1 mm for 
f=100 mm around the 23 degree of field angle, but this lens shows 0.24.0. 3 mm as 
the value of the astigmatism. It is said that this lens has very little astigmatism 
and curvature of the field. Around the field angle of 30 degress, however astigmatism 
becomes considerably greater but this value is only a little larger than the ordinary 
camera lens. Accordingly, around the perimeter of the format, the image quality 
has apparently become poorer, however, approximately 80% out of total format has 
a very clear image. 
The distortion curve is known as the Barrel type. The value of this distortion q 0 
is minimal, that is 0. 3 %, compared with the ordinary camera lens. 
2.4.3 Measurement of Resolving Power of Photography 
Resolving power is defined as the ability to distinguish fine details in photo- 
graphs. It is usually represented by the number of lines per milimeter which can 
be separately distinguished in the photograph. 
The following Fig. 7 shows the chart used for the resolving power test. This 
chart is used to find the limitation of the smallest line spacing that may be 
separately distingished in various types of patterns, each of which is shown in 
three lines with the same clearance. The stereo-camera was set at a distance ^ 
of 120, 150, 200, 250 and 300 centimeters from the chart and the base line of the 
camera was placed parallel to the chart board. 
Fig. 8 is a diagram showing the result of the resolving power in connection with 
the above mentioned distance. Both lenses have the same tendency as shown in 
the disgram but at the extreme distant point, the resolving power is the best. 
    
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Fig. 7 Chart for Resolving Power 19610 200 250 309 
Distance between camera and chart 
Fig- 8 Resolving Power Diagram of 
1.1.S. Camera 
Experiment 
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