with vigor, 
:xtensively. 
nd promis- 
ked within 
  
in axial 
1 north- 
Ltd. Photo 
1 also, and 
een photo- 
gical facts 
marily for 
g area, has 
It may be 
t from the 
nown, it is 
erpretation 
  
  
   
  
   
     
   
  
  
  
  
  
  
   
  
  
  
  
  
  
  
  
  
  
   
   
  
  
      
(657) 
THE O.D.S., A NEW INTERPRETATION STEREOSCOPE 
by 
R. Roelofs, Delft, Holland. 
Of the many links which constitute the photo-reconnaissance, photo-inter- 
pretation chain, the weakest Ones are believed by many to fall in the category 
of Photographic Interpretation Equipment, Materials and Methods. These are 
the approximate words of our present chairman, Commander Colwell, in his 
contribution to the excellent report of the International Commission VII. They 
evidence the dissatisfaction felt by many photo-interpreters when endeavouring 
to ascertain all the information the aerial photographs contain. 
Some years ago Mr. Katz of Wright-Patterson Air Force Base depicted the 
situation in still stronger words by saying: *this matter of photographic-inter- 
  
Fig. 1. The O.D.S. stereoscope in use for 
scanning stereoscopic pictures. 
pretation strikes us as being a very much unbalanced situation, wherein we may 
take a million dollar airplane, a hundred thousand dollars worth of cameras, a 
half dozen rolls of film, one of which (for the K-40 camera) is going to cost 
about $ 400... we take off on a very hazardous mission in the sense of military 
and social economics... when the photo-interpreter gets around to abstracting 
the information he uses a 10 cent magnifying glass..."