Stereoscopy with objects in distance?

Honestly, in my experience(wich is about a couple years, only, so I may be wrong) with clinical work, even before 20/30 metres, most of the people can't really tell distances with disparities with a normal contrast and ilumination. Most of the time, they rely on paralax, and even then they rarely perceive small and slow paralax movements.
I've seen more papers like the one posted, and they always have the same conclusions, so little to add here but another confirmation of what has already been said.

"RandyWilliams" wrote:
Honestly, in my experience(wich is about a couple years, only, so I may be wrong) with clinical work, even before 20/30 metres, most of the people can't really tell distances with disparities with a normal contrast and ilumination. Most of the time, they rely on paralax, and even then they rarely perceive small and slow paralax movements.
I've seen more papers like the one posted, and they always have the same conclusions, so little to add here but another confirmation of what has already been said.

We rely on different visual clues for distant objects, such as variance from expected size, occlusion by closer objects, and "fog effects" due to atmospheric filtering.

and all of those clues, are monocular. No binocular vision is involved.

Here's a link to an informative paper on depth cues which expands on the ones geekmaster mentions:
Perceiving layout and knowing distances by Cutting & Vishton 1995.
http://pmvish.people.wm.edu/cutting&vishton1995.pdf

The cues they list are as follows:

Occlusion
Relative Size and Density
Height in Visual Field
Aerial Perspective
Motion Perspective
Convergence and Accomodation
Binocular Disparity, Stereopsis and Diplopia

There are graphs at the bottom for quick reference.