We use Optical Character Recognition (OCR) during our scanning and processing workflow to make the content of each page searchable. You can view the automatically generated text below as well as copy and paste individual pieces of text to quote in your own work.
Text recognition is never 100% accurate. Many parts of the scanned page may not be reflected in the OCR text output, including: images, page layout, certain fonts or handwriting.
70mm Test Vehicle Recorder
By CHARLES T. LAKIN
A small camera is described which takes -g by 2^ in. pictures at rates up to 450 frames/sec on 70mm film. The film is stationary during exposure. The total weight of the camera is 25 Ib. Its long thin aperture shape, its high frame rate and its small size should make it a useful tool for work in ordnance and in aircraft and machine design.
_L HE 70mm Test Vehicle Recorder (TVR) is a specialized camera designed for high-speed measurements. It was designed originally for photographing rockets being launched from aircraft in flight, but it is ideally suited to photograph such things as high-speed vehicles, missiles, aircraft components in flight or machine motions.
Description
The 70mm TVR has the specifications shown in Table I.
Although the frame rate is very fast the film is held stationary during the exposure; therefore, it is not necessary to compensate for film motion either optically or by means of a high-speed shutter.
The exposure is equivalent to that of a 90° rotating shutter. Any smaller
Presented on October 9, 1952, at the Society's Convention at Washington, D.C., by Carlos Elmer for the author, Charles T. Lakin, Code 3531, Aviation Ordnance Dept., U.S. Naval Ordnance Test Station, Inyokern, China Lake, Calif. (This paper was first received September 24, 1952, and in revised form on March 16, 1953.)
sized opening can be used by disassembling the camera and replacing the present shutter with one having the desired opening.
The lens now used is a Zeiss Universal Tessar, 2-in. focal length, which has a maximum aperture off/4.5. Its angular coverage is 58£° across the 2^-in. aperture measurement. A little better resolution is obtained at the corners of the picture if a Zeiss Universal Tessar, 3-in. focal length, //3.5 lens, covering 42°, is used.
The motor now used is ^-horsepower, 28-v d-c. This motor was chosen because the present use of the camera is to photograph objects aboard an aircraft in flight.
Table I
Nominal frame size Maximum frame rate Total film load Total weight Length, including lens Height, including base plate
i X 2} in. 450 frames/sec 80ft 25 Ib 9} in.
8} in.
Width, including motor 11 J in. Width, excluding motor 6} in.
June 1953 Journal of the SMPTE Vol. 60
671