ed : 
Vv 
" 
0.02 mm. The camera is used on a tripod and can be swung and tilted as desired. The glass plates 
are loaded in normal cassettes. 
Disposition of camera set-up 
  
Several factors contribute to the determination of focussing distance and base : 
The distance between camera and model should be as small as possible to get a large 
photo scale. It must, however, be large enough that the whole model lies in the depth of field. 
Moreover the base/distance ratio must remain within the instrumental range of the WILD A 8. 
According to Finsterwalder "Photogrammetrie" the following relation determines the depth of 
field : 
   
    
  
| 
| 
cse 
i p cad 
= | 
a 
| 
  
   
  
  
  
  
aperture 
d soa De 
Ward dyr = 7 : 
y- 7 vu C 
Using the data of the WILD objective, calibrated focal length f = 115 mm and aperture 
2d = 3.4 mm at aperture 32 as well as a mean object distance of a = 2.8 m and a circle of confu- 
sion diameter 2z = 0.01 mm one will get the values dy, - 0. 34 m and dy, = 0.45 m, that means a 
region of image sharpness of 0. 79 m wherein the model with its height of about 0. 70 m had to be 
placed, The mean object distance of 2.8 m is convenient too for one may reach a suitable model 
scale of 1:10 for mapping in the instrument WILD A 8, The Sinar camera has an image distance 
b = 120.0 mm if the distance between model and camera is 2, 8 m. Assuming an effective length 
of 1' = 17 cm on a 13 x 18 glass plate the real length 1 may be derived from geometrical relations : 
The photogrammetric base B depends on the largest model, the stadium, which has a 
length of 3.3 m, With an effective length 1 = 4, 0 m we calculate a base of 0.7 m which corresponds 
to a forward overlap of more than 80 %. 
  
  
E. NET 
N 
B / pg 2,8 2 
(=l > * 017 gz (m = 40m 
| 7 
EY. 
a I, N 
LA N 
N 
A . 
zd \ 
ki — 8 —+> — 3,3 m —= 
| 
  
  
55 ee