How To View Stereo-Pair Photographs

This section is a general tutorial on viewing stereo-pair images to create a 3D image out of a right and left pair of images. The stereo images on this website, in the section called "3D images", use 3 images (left, right, left) instead of a pair (left, right) so that wall-eyed or cross-eyed viewing can be utilized without having to switch the position of the images. By either utilizing wall-eyed or cross-eyed techniques a fourth image will appear from the 3 provided and one of the 2 images in the middle, one will be the correct 3D image and the other will be the opposite (relief being mound and vice-versa). The following information (below) is in regards to stereo-pairs which are 2 images, left and right.  

 

Stereo-Pairs may be viewed wall-eyed or cross-eyed.

Wall-eyed Viewing-

 

This is when the left eye views the left picture and the right eye views the right picture. Generally, stereo-pairs in print are arranged for wall-eye viewing, unless otherwise stated. Cross-eye viewing of these images causes the relief information to be reversed. A mound becomes a pit and vice-versa.

1. Hold the stereo pair at a comfortable, viewing distance, wearing your glasses if you normally wear them.

2. The stereo-pair should be approximately in the center of your visual field and evenly illuminated. 

3. Looking "through" the paper, look to the distance.

4. A third image will appear between the left and right pictures.

5. Without converging the eyes, slowly focus on the third, center image.

6. A 3D picture will emerge.

  

Cross-eyed Viewing-

If cross-eyed is more comfortable, then the images need to be switched. This arrangement is more normal for stereo-pair projection, since it is impossible to relax the convergence at large distances.

1. Hold your finger 4-5 inches in front of your nose.

2. Focus on your finger - in the distance the two images become one stereo image, with the separate images still visible on either side.

3. Slowly focus on the center image without reconverging the eyes. The center image becomes sharp and in 3D.

  

Cross-eyed or wall-eyed viewing (Like the images on this site under "3D images".)-

Relax your eyes until you see a fourth image appear. Depending on whether  you  cross (cross-eyed viewing) or separate your eyes (wall-eyed viewing), one of the two images in the middle will be the correct 3D image and the other middle image will be the opposite direction 3D.