This silent film from WWII shows what appear to be tests of an aircraft gun sight aiming camera, or GSAP Camera. The film provides an interesting “gunner’s eye view” of the reticle or firing ring that a WWII gunner or pilot would have seen, complete with a “dot” in the center. This was likely a type of reflector sight although the camera doesn’t give a good impression of how the ring would disappear when viewed from attitudes not 90-degrees forward . The start of the film shows a fairly normal view of the sky as seen by a standard GSAP camera, with a “notch” visible on four sides and a “lever” on the upper left. At :28 the reflector is added with strong effect.
A reflector sight or reflex sight is an optical device that allows the user to look through a partially reflecting glass element and see an illuminated projection of an aiming point or some other image superimposed on the field of view. These sights work on the simple optical principle that anything at the focus of a lens or curved mirror (such as an illuminated reticle) will look like it is sitting in front of the viewer at infinity. Reflector sights employ some sort of “reflector” to allow the viewer to see the infinity image and the field of view at the same time, either by bouncing the image created by lens off a slanted glass plate, or by using a mostly clear curved glass reflector that images the reticle while the viewer looks through the reflector. Since the reticle is at infinity it stays in alignment with the device the sight is attached to regardless of the viewer’s eye position, removing most of the parallax and other sighting errors found in simple sighting devices.
Since their invention in 1900, reflector sights have come to be used as gun sights on all kinds of weapons. They were used on fighter aircraft, in a limited capacity in World War I, widely used in World War II, and still used as the base component in many types of modern head-up displays. They have been used in other types of (usually large) weapons as well, such as anti-aircraft gun sights, anti tank gun sights, and any other role where the operator had to engage fast moving targets over a wide field of view, and the sight itself could be supplied with sufficient electrical power to function. There was some limited use of the sight on small arms after World War II but it came into widespread use after the late 1970s with the invention of the red dot sight, with a red light-emitting diode (LED) as its reticle, making a dependable sight with durability and extremely long illumination run time.
Reflector sights are also used in civilian applications such as sights on surveying equipment, optical telescope pointing aids, and camera viewfinders.
We encourage viewers to add comments and, especially, to provide additional information about our videos by adding a comment! See something interesting? Tell people what it is and what they can see by writing something for example: “01:00:12:00 — President Roosevelt is seen meeting with Winston Churchill at the Quebec Conference.”
This film is part of the Periscope Film LLC archive, one of the largest historic military, transportation, and aviation stock footage collections in the USA. Entirely film backed, this material is available for licensing in 24p HD, 2k and 4k. For more information visit http://www.PeriscopeFilm.com
