(31) 
Austria 
'1 he camera mounts used provide levelling about two axes and use rubber 
as a supporting material for vibration isolation. A camera port glass is used 
with a permissible wedge of 0-01 mm. Practically all photography is done in 
clear weather. Exposures are determined by experience. For the RC-5 1/150 
of a second at f 4 • 2 or f 5 • 6 is typical. For the RC-7 1/300 of a second at f 4-2 
is usual. Photographic altitudes are 4,000 to 5,500 metres above sea level for 
the RC-5 and 2,000 metres for the RC-7. With both a statoscope is photo 
graphed by an auxiliary camera. 
Canada 
The 6" Ordnance Survey Camera is used in the mount supplied for it by 
the manufacturer. This uses rubber as a vibration isolating material. The 
Eagle IX camera is used in a mount in which rubber is the supporting medium. 
The Fairchild F224 Cartographic camera is used in the F231 mount which has 
Lord type shock mounts depending on rubber in shear. The K17B camera is 
used in a sponge rubber mount. Tri-camera mounts of the type shown in Fig. 9 
have been developed for the 6" cameras with 9" x 9" format to maintain the 
camera relationships within 2 minutes of arc even with camera interchange. 
They are supported on foam rubber. Eagle V cameras used either singly or in 
Fig. 9 Royal Canadian Air Force tri-camera mount for three K17B or F224 cameras