Selected instruments and techniques
Super wide angle camera
Description: Aerial Camera with angular field of 1209, format 9" x 9",
focal length 3-1/2".
Photointerpretation application: For taking small scale color or
black-and-white photographs from relatively low altitudes. Increased
angular field (1200) increases vertical exaggeration with normal
stereoscopic overlap (60%). Advantageous for geologic study or terrain
analyses of some areas.
Remarks : Ae ARI commercially. (Wild Heerbrugg, written communication,
1959.
New plotting instruments
(Suitable for use with color and super wide angle photography)
Description: Mechanical projection-type instruments, designated B-8 and B-9,
that are relatively inexpensive, and will accommodate photographs taken
with 3-1/2-inch focal length cameras. The B-8 Plotter will accommodate
full size color transparencies.
Photointerpretation application: Any interpretation problem whose solution
would be facilitated by use of a third order instrument for plotting
and measuring. Particularly suitable for problems involving super wide
angle photography or color photography.
Remarks: Available commercially. (K. E. Raymolds, written communication,
1959.)
Stereoscope for viewing uncut film
Description: Stereoscope (fig. 2) designed for viewing on x 9" or 9" x 18"
uncut aerial photograph transparencies. Modifications of this
instrument are available for viewing 4-1/2" x 4-1/2" film. One version
of this instrument has 3x magnification, another has powers of 2-1/2x,
6x, and 12x.
Photointerpretation application: Any photointerpretation problem wherein
storage, use, or time of interpretation would be facilitated or
shortened by maintaining transparencies in roll form.
Remarks: Available commercially. (R. T. Shone, written communication, 1959. )
Stereoscope mount for double viewing
Description: A wooden mount (fig. 3) to raise two mirror stereoscopes and
fix them in an oblique position.
Photointerpretation application: To make it possible for two interpreters to
view the same pair of photographs simultaneously without special
equipment. (Professor Carlos Eugenio Magarinos Torres, written
communication, 1959.)
