2 
parts of "the model-forest's ground? that will be visible in 
a single photograph, will be exposed. Remaining parts of the 
"ground" are hidden by the model-trees. 
Fig.l 
The flying altitude 
was choosen to 200C m and the 
photography is supposed to be 
performed with a normal angle 
camera (21;18-18 cm) and a 
Wide-angle camera (20;3%0+30cm) 
If the model is illu- 
minated by two lamps, it will 
be possible, to investigate to 
wich extent the ground is 
Stereoscopically visible, and 
to wich extent it is visible 
from one or the other exposure-