vs 
  
  
the most cases, when photogrammetry is employed for non cartographic purposes, the restricted 
financial possibilities and the working conditions allow and require the use of plate cameras. 
The use of plates request no feeding device between one shot and the following and no 
flattening on the focal plane (in fact 24 x 24 cm size plates are available on the market with a 
discrepancy of + 0.00002 inch per linear inch from the theorical value). These need only to be 
laid on the focal plane through simple and cheap devices. 
We must point out anyway that plates are more expensive and heavier than the film. 
Now the plastic plates begin to be available on the market, thus reducing the sensitized 
material weight. 
Table 2 summarizes benefits and drawbacks of the different available solutions. 
  
  
ADVANTAGES DISADVANTAGES 
Film camera The film is: cheap The film must be flattened: 
light : : 
16 pneumatically = not very well working 
small sized : : 
and weight increase 
eas to use . . 
y = causes vibrations 
Glass plate - the plate is easily 
scratched and must be 
well clean 
The film requires complicated equipment for 
  
  
  
development 
Plate camera - very good flatness of the plate The plates are: = expensive 
- least plate distortion - remarkable size and weight 
- safe working - difficult stocking 
- light and small sized 
- easy development and printing 
Table 2 
Comparison between sensitized film and plates 
3.4, Camera simple design 
  
The photogrammetric survey for non topographic purposes needs the employment of 
cameras having features fully different and sometimes in contrast with those of the aerial 
photogrammetric cameras. 
Practically 24 x 24 cm film only is used for the aerial survey : all the cameras have the 
same size and their lens is replaceable to change the focal length. This feature, with the necessity 
of photographing a large ground surface, allowed the serial construction of the aerial cameras. 
Therefore the cost of an aerial camera is comparatively low yet the design is complex and the 
optical processing is characterized by a refined accuracy. 
On the contrary the non topographic survey offers particular problems, thoroughly 
different between them. 
The camera used for architectural surveys cannot be used to survey object in swift 
motion; the camera for photography at a microscope is not absolutely suitable for the high 
precision survey of car-bodies. 
Furthermore how many are the photographs to be made for our particular purpose 
compared with those made by an aerial camera ? Surely a number 100 or 1000 times lower! 
AD