It is possibile to appreciate depth in stereoscopic pairs through some ocular exercises.

As for the anaglyphs, we suggest to NOT attend these techniques to people suffering of epilepsy and also to suspend them if during the tests you feel any form of pain. However, in our experience, this happens only in a few number of cases.

IT IS IMPLICIT BUT WE WANT TO GO OVER AND OVER IT AGAIN: IN SOME CASES, EVEN IF RARELY, THESE EXERCISES, ESPECIALLY THE CROSS-EYED, CAN BE ORIGIN TO PAINS IN THE VISION. YOU ARE FREE TO DO OR NOT TO DO THEM AND WE DON'T ASSUME ANY KIND OF MORAL AND CIVIL RESPONSABILITY RELATED TO EVENTUAL TROUBLES DERIVING FROM THE UTILIZATION OF THESE TECHNIQUES.

In the 2D vision (the one we use to look at a photo, for instance), our eyes focus on the plan of the scene.

If you have a stereo pair available (look at the section    Creating a 3D image on how to obtain it) it is possible to view the three-dimensional related image through Cross-Viewing (also called Cross-eyed Viewing), which consists in making each eye looking at a single image by crossing the eyes, or through Parallel-Viewing in which eyes are converged in a distant point placed far behind the surface (print or monitor) in which the stereo couple is placed.

A certain training is of course needed but the advantages are huge in comparison to anaglyphs:

• you don't need specific devices (3D glasses);
• problems related to ghosting (i.e. the presence of zones in which our brain hardly distinguishes the two images of the pair) are diminished;
• colours are preserved

 

Cross-Viewing

These are the steps:

• get the stereo pair and cross the images (right image on the left and left image on the right);
• cross eyes until the two images get three;
• place your hands in front of your face in order to "hide" the side images and let only the central one to be visible;
• focus on the visible portion and relax: you got the 3D image !

The following example is a stereo cross pair representing two artists in New York who shoot pictures practising the pinhole method (we strongly suggest you a research about that matter: is just like rediscover the roots of Photography).

Cross-Eyed Viewing

If it seems too small for you, follow the link for a    1000x650 pixels one.

 

Parallel Viewing

The steps:

• get the stereo pair and put the two images side-by-side (no need to cross them!);
• look at the center of the pair but focus on a point behind the screen of the monitor;
• when you get three images, try to concentrate on the central one

Parallel Viewing

This Parallel stereo pair has been shot in Battery Park (NYC).

Some people are able to use the Parallel Viewing method but not the Cross-eyed and viceversa; other no one at all. A little patience and exercise are needed to use at least one of the two: we guarantee that it worths while.