(510) 
the orthographic view, the easel is merely turned perpendicularly to the 
collimated beam. It is obvious that obtaining sharp focus for this print is difficult 
and special scanning apparatus is necessary. The example in the display was not 
made on the Bench Camera since a special scanning apparatus was not available. 
Consequently the lines of sight along the y axis are not exactly parallel and are 
slightly elongated. 
The oblique orthographic view also retains a highly simplified scheme for 
measuring horizontal and vertical distances in the picture. This view varies 
from the parallel oblique in that the y and z coordinates can be varied but 
never exaggerated. Although the scales of y and z may be varied they will be 
uniform on a particular plane. Because of this variation in scale the oblique 
orthographic view does not offer quite the simplicity of measurement that is 
inherent in the parallel oblique. 
Another interesting view which can be obtained with the Bench Camera 
is the inverse central perspective (see Fig. 4) which is complementary to the 
central perspective view normally taken with the conventional camera. The 
inverse central perspective places the point of view behind and below the ob- 
ject being photographed. 
Fig. 6 illustrates one step grid transformations which have been made with 
the Bench Camera. Using the camera in telecentric alignment as a shadow pro- 
jector, it is possible to make “parallel” restitutions in one step, by silhouetting 
a positive map line plate onto the photographic plate. The photographic plate 
is placed as close as possible to the positive. 
It seems that the principles illustrated here have a wide application in the 
field of cartography and photogrammetry. From a cartographic standpoint, it 
is apparent that views of this type will enable the cartographer to present ter- 
rain information in a more pictorial form and still retain scale accuracy. It 
seems that graphics produced by these methods should be of considerable 
advantage for aircraft approach and landing and might have further applica- 
tion to radar prediction patterns. Simply stated, these principles allow for the 
production of graphics which illustrate the view of an observer from an infi- 
nite number of points toward the horizon and which, in addition, possess the 
characteristics of scale fidelity for precise measurement in all three dimensions. 
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