The camera can take the vantage point of a seated observer, who rises from the seat. A camera positioned on the back of a train will record a flow pattern indicating the observer's vantage point is rushing away from the distant horizon. Mountains on the horizon will decrease in angular subtense slowly. Nearby railroad ties will decrease in angular size swiftly, and more distant ones will decrease in size comparatively slowly. Perspective is the master key to binocular vision.
Binocular vision obtains two inputs.
It samples from the optic array at one vantage point, and a neighbouring vantage point. The differences in the optic pattern, including texture gradients, projected to the two eyes is information for depth. The relationships present in the optic patterns are governed by perspective principles. Of course, there are many matters governed by perspective, and many laws of perspective. It may be too that vision is fairly rough and ready at times in its use of perspective.