|Aerial Photography From Your R/C Model|
Unless photographing very wide areas that require it, this altitude is often less than ideal. There are a number of problems: For a start, atmospheric haze increases with altitude, affecting picture clarity.
Also, if a smaller object such as a house is being photographed, a telephoto lens must be used, requiring a high shutter speed to prevent motion blur, which in turn requires fast film that tends to be grainy and have poorer contrast.
Low-altitude aerial photography avoids these problems altogether. At lower altitudes, there is less atmospheric haze between camera and subject, resulting in noticeably clearer photos.
Also, by being closer to the subject, a telephoto lens is not required, which allows slower shutter speeds and more light to the film. This in turn allows slow, fine-grain, high-contrast film to be used.
From the normal operating height of a light aircraft, to make the house fill the frame, one would need a telephoto lens.
The resulting "tunnel vision" misses out the horizon and all the other features between the house and the horizon.
Telephoto lenses also destroy perspective, a critical element in our depth perception, where closer objects appear bigger.
This, combined with the enhanced perspective effect of the lens, creates a strong sensation of "being there".
We chose the remotely piloted helicopter as a good platform, because of its compactness, manoeuvrability and height flexibility.
Next time I'll be looking at methods to combat vibration - the aerial
Contributed by Richard Shelton at HiCam.
Web Site: HiCam Aerial Photography
(These articles first appeared on the Hi Cam web site
and have been reproduced with the owner's permission).