3 
elements of drift setting, tip and tilt made with the (\JF1 are 
transferred automatically to the aerial camera through a new 
servo-motor camera mount, the Wild PAl/2 Universal Mount (Fig.2). 
The Navigation Sight consists essentially of an erect-image 
telescope supported in a cardanic mount. Its principal optical 
axis can be plumbed by turning tuo footscrews to centre a circular 
bubble. The telescope objective can be swung forward continuously 
through up to 50°, at which position a view of the heading from 
horizon almost to nadir is seen. Its field of view is 97° approxi 
mately . 
Fig.3 shows the reticle of the Navigation Sight and explains the 
pattern of lines, which are curved to compensate for the barrel 
distortion of the telescope. Superimposed on this pattern in the 
Flight direction 
Fig, 3 Reticle of the Wild NF1 Navigation Sight 
Uertical position 
1. Time interval lines for 60% 
overlap with super wide angle 
camera 
2. Frame of wide angle photograph 
3. Frame of normal angle photograph 
4. Circular level 
Objective tilted 5D° 
5. 
Horizon 
vanishing point 
6. 
Horizon 
7. 
Width 
of 
super wide 
angle 
strip 
8. 
Width 
of 
wide angle 
srrip 
9. 
Width 
of 
normal angle strip