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Many workers?-® have since discussed the problems of aerial camera 
motion and suggested remedies. However practical efforts to minimize 
image motion, in civilian aerial survey photography still leave room 
for improvement although some useful progress has been made. 
This report will point out the resolution loss being experienced, 
describe techniques for the study of vibration of cameras in flight, 
and present résults for a number of aircraft and camera mounts. Some 
shortcomings of anti-vibration mounts will be discussed and improve- 
ments suggested. 
2. PRESENT RESOLUTION LOSSES 
The loss of image sharpness that can occur from excessive image 
motion is generally understood and generally avoided by the use of high 
shutter speeds. That this use of high shutter speeds causes indirectly 
a loss of image sharpness does not seem to be as widely understood. 
If image motion did not have to be controlled by high shutter 
speeds, it would be possible to achieve immediate gains of the order 
of 35 to 55% in resolving power. Consider figure 1, replotted from a 
study of resolution in a 15 cm focal length, 23 x 23 cm format, survey 
camera?. If instead of having to use Kodak Double X film (DX) at f/5.6 
to obtain adequate exposure at a high shutter speed. (e.g. 1/890 s), it 
were possible to use PlusX (PX) at f/11 and 1/150 s or Panatomic-X (FX) 
at f/11 and 1/65 s, area weighted average resolution at the optimum 
scene brightness in the typical range would increase from 18 mm^! to 
24 mm-! or 28 mm-!, respectively. Considering resolution averages over 
the representative scene brightness range weighted by the typical 
distributions in that range!?, corresponding values would increase from 
17 mm! to 23 mm^! or 27 mm-!. Such a gain in resolution could be 
applied to improve picture quality or to reduce photo scale or to a 
combination of the two. The economic gain from improved picture 
quality would be real in terms of interpretation time and accuracy, but 
would be hard to evaluate quantitatively. However it is simple to 
evaluate the possible effect of reducing scale to just maintain the 
same ground resolution. For the two steps of improvement mentioned, 
photo line miles would be reduced to 75% or 64% of the value with DX, 
f/5.6, and 1/890 s, and the number of photographs to 56% or 41%. It 
thus seems reasonable to conclude that considerable economic gains 
could be achieved by a serious study of image motion and development of 
better methods for reducing it. 
3. MEASUREMENT OF CAMERA VIBRATION IN FLIGHT 
The technique of measuring the angular vibration of an aerial 
camera by flying over lights at night with the camera shutter open 
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