Graflex.org

disemjg · Joined: 10 Jan 2002 Posts: 474 Location: Washington, DC

I just got this oddball device, which is an Ilex shutter with no optical elements, just a flat piece of glass at the front to keep your fingers out of the shutter. The back of the shutter is fitted with a large tube and a clamping screw, evidently to slide over some projection lens.

What was this for? My best guess is for some form of flash training, where an image was projected for a moment and you were supposed to be able to identify what the image had been. Something like aircraft identification training.

I'll ask Les to post some photos.

glennfromwy · Joined: 29 Nov 2001 Posts: 903 Location: S.W. Wyoming

My understanding is these things were used during the war to train pilots to instantly recognize enemy aircraft. It was placed on the lens of a slide or film strip projector.
I guess if you saw the thing flash a picture enough times, the images would stick to your brain. I have one I was using as a front mounted shutter but it's worn out and I don't think I can fix it any more.
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Glenn

"Wyoming - Where everybody is somebody else's weirdo"

Dan Fromm · Joined: 14 May 2001 Posts: 2139 Location: New Jersey

When I was in high school I took a speed reading course that used a device called a tachistoscope to project letters, words, and short sentences for a very short period of time. It was basically a film strip projector (remember them?) with a shutter in front of its lens. This is basically Glenn's application.