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View Full Version : Gun camera film speed reduction



Lurch1962
07-17-2007, 07:08 PM
In a 1943 P40 manual, it was stated that the gun camera (either N-2 or N-6, which used 16mm film) had a 50-foot film magazine, yielding approx. 15 seconds recording time. (Not too much longer than the ~10 seconds of firing time!)

Fifty feet of 16mm film has about 2,000 frames (40 frames/foot) so 2,000 frames / 15 seconds = 133 frames/second. At a typical playback speed of 24 frames/second, the action would be slowed by a factor of 5.5, i.e., between 1/5 and 1/6 normal speed. Imagine playing them back at normal speed--the action would be quick indeed!!

But I suspect that two or possibly more rates were selectable, and that this represented the shortest recording time (slowest motion on playback).

--Lurch--

Lurch1962
07-17-2007, 07:08 PM
In a 1943 P40 manual, it was stated that the gun camera (either N-2 or N-6, which used 16mm film) had a 50-foot film magazine, yielding approx. 15 seconds recording time. (Not too much longer than the ~10 seconds of firing time!)

Fifty feet of 16mm film has about 2,000 frames (40 frames/foot) so 2,000 frames / 15 seconds = 133 frames/second. At a typical playback speed of 24 frames/second, the action would be slowed by a factor of 5.5, i.e., between 1/5 and 1/6 normal speed. Imagine playing them back at normal speed--the action would be quick indeed!!

But I suspect that two or possibly more rates were selectable, and that this represented the shortest recording time (slowest motion on playback).

--Lurch--