Figure 6.1 – View through a Zograscope

This is a stereo image of looking at a vue d'optique through a zograscope. You are looking straight ahead through a biconvex lens. Behind it is a mirror held at 45 degrees. The engraving, which lies flat and upside down on the table below, is reflected in the mirror. If you can freeview it (cross eyed) you can get some idea of the depth effect.

 

There is a lot of apparatus visible here that distracts from the image. Without masking there is still a weak depth effect. Eighteenth-century people were impressed by it and were convinced enough of the zograscope's value that those with means spent quite a lot of money on these devices and collections of images for them.

 

The exposure of the mechanism of viewing at the expense of the image makes the experience less immersive. The zograscope may have been considered a "philosophical toy" whose very purpose was to educate in the mechanism of illusion.