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Old December 14th, 2012, 11:20 AM   #17 (permalink)
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Originally Posted by dreadnatty08 View Post
Remember making a camera with a shoebox.
Ah yes, pinhole lenses and narrow slit lenses. Favorite projects of my childhood.

Pinhole cameras - has anyone seen the Camera Obscura at the Cliff House in San Francisco? You pay your admission to go inside a 20-foot square building/camera to see live panoramic ocean/beach views projected on a large plate by the the rotating lens on the roof.

Slit lenses - light bends slightly around the edges of solid objects. That is how pinhole lenses work. Narrow slits also can be lenses. If you look through a narrow slit between your fingers, at the proper spacing you will see narrow grey bands that are interference patterns of the light bending around the edges of your fingers. Spaced properly the slit between your fingers becomes a lens. So . . .

. . . when the Navy sent me and one of my ROTC buddies from Chicago to Great Lakes navy base near Milwaukee for our jet pilot physicals, at the end they dialated our eyes for an eye test then sent us home. Not wanting to wait for our eyes to recover before making the drive back to Chicago, we used slit-between-the-fingers lenses and could see pretty well. But we drew some pretty astonished stares as we cruised down the Interstate in my top-down convertible sports car with our hands covering our eyes
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