Cross eyed stereo 1
Batch of film spools

 
A stereo photo was made from the subject with a normal camera. Two photos were taken while the camera was shifted about 5 cm horizontally between them, simulating the distance between the eyes and registering the subtle differences in image content left and right.

 
 
 
 
The compound image can be viewed in 3D without any aid and at a normal distance by crossing your eyes until you see 3 images side-by-side. Focus on the middle image and adjust the amount of crossing until it stands out. After that you can adjust the viewing distance for comfort.

Please click on the image for a larger version.