Zograscope

A zograscope is an optical device designed to disrupt depth cues when looking at a flat picture and create the feeling that you're looking at a real scene.

It consists of a large lens held vertically in a frame, and attached to an angled mirror. The viewer looks through the lens at the mirror reflection of a picture laid out horizontally on a table.

The device interferes with stereoscopic cues, and it collimates the light, resulting in an impression that you're looking at a real scene.


Special perspective prints were manufactured to work optimally in these devices.

Other zograscopes were portable units made to look like a fake book when folded up.


Optical instruments like this were popular in the 18th century as a form of parlor entertainment.

I've seen similar devices, such as cabinet stereoscopes and peep boxes. One I saw recently had dual eyepieces with anamorphic images mounted on the inside of the box, which adds even more to the impression of virtual reality.
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Resources
• You can make your own zograscope with an inexpensive Fresnel lens (less than $10) mounted in a cardboard box.

• Book: A Companion to Early Cinema

• Read more online about zograscopes and perspective prints

• Wikipedia on Zograscope