The general philosophy behind the use of superwide-angle photography is to 
reduce the number ofphotographs necessary to cover the area tobe mapped. This 
implies the retention of high altitude flights which, together with the very short 
focaldistance of 230 mm x 230 mm photographs, produces small-scale photography. 
Since each photograph covers a large area, the effect of earth curvature becomes 
more prominent and affects the plotting accuracy in elevation. In order toimprove 
this situation the manufacturer of the Super-Aviogon also produces compensation 
plates for various flying heights that, in addition to correcting the radial distortion 
of the photographic lens, eliminates the effect of earth curvature. The first tests 
carried out with Super-Aviogon photographs on the Wild Autograph A-9 revealed an 
accuracy slightly worse than that obtainable from regular wide-angle photographs 
on first-order plotters. No doubt this result is due first of all to the reduction of 
the original superwide-angle photographs to half-size for plotting on the Autograph 
A-9. There is not enough reliable information on the use of the original-size 
superwide-angle photography for a complete assessment of its performance. 
As for other novel photographic elements, it appears that only a few coun- 
tries have delved further into a more extensive use of infrared emulsions to 
improve the definition of topographical detail in the photographic image. Rather, 
special emulsions have been used for photo-interpretation purposes. Also, color 
emulsions did not find wider applications in the mapping field. 
Plotters and Plotting Technique 
As a result of the distinct improvement in survey photography in recent 
years, the flying height for photogrammetric operations has been generally 
increased. This in turn has imposed high requirements for plotting equipment. 
Therefore, plotters that use greatly-reduced diapositives are gradually being 
abandoned. This applies mostly to the Multiplex, which is being replaced by 
plotters that are based on a similar principle but are capable of using either 
contact diapositives or reduced diapositives muchlarger than the Multiplex plates. 
This is a very healthy trend which distinctly marks the direction of the general 
development of present photogrammetric technique. 
Parallel to this change there is a strong trend toward automation in the 
plotting technique. The most basic change will no doubt be the future introduction 
of the Analytical Plotter. However, since this instrument is still in the pre- 
prototype stage we shall turn our attention at present to equipment already built 
whose efficiency has been tested in actual experiments. 
  
I have in mind the Orthophotoscope and the automatic stereoplotting device 
and the possible effect both these pieces of photogrammetric equipment may have 
on small-scale mapping. 
The Orthophotoscope developed in the U.S. A. permits a precise rectifi- 
cation of aerial photographs, and takes into account even minute differences in 
ground elevation. In addition, the rectified photographic image of the terrain can 
be completed by precise contour lines. There should be no special difficulty in 
achieving a high degree of automation in this process.