1. Motion Depth Cues – Motion 1. Parallax

2. Motion Depth Cues – Parallax

3. Motion Depth Cues – Parallax – points at different locations in the visual field move at different speeds depending on their distance from fixation

4. Motion Depth Cues – Parallax

5. Seeing in Stereo

6. It’s very hard to read words if there are multiple images on your retina

7. Seeing in Stereo It’s very hard to read words if there are multiple images on your retina But how many images are there on your retinae?

8. Binocular Disparity Your eyes have a different image on each retina –hold pen at arms length and fixate the spot –how many pens do you see? –which pen matches which eye?

9. Binocular Disparity Your eyes have a different image on each retina –now fixate the pen –how many spots do you see? –which spot matches which eye?

10. Binocular Disparity Binocular disparity is the difference between the two images

11. Binocular Disparity Binocular disparity is the difference between the two images Disparity depends on where the object is relative to the fixation point: –objects closer than fixation project images that “cross” –objects farther than fixation project images that do not “cross”

12. Binocular Disparity Corresponding retinal points

13. Binocular Disparity Corresponding retinal points

14. Binocular Disparity Corresponding retinal points

15. Binocular Disparity Corresponding retinal points

16. Binocular Disparity Points in space that have corresponding retinal points define a plane called the horopter The Horopter

17. Binocular Disparity Points not on the horopter will be disparate on the retina (they project images onto non-corresponding points)

18. Binocular Disparity Points not on the horopter will be disparate on the retina (they project images onto non-corresponding points) The nature of the disparity depends on where they are relative to the horopter

19. Binocular Disparity points nearer than horopter have crossed disparity points farther than horopter have uncrossed disparity The Horopter

20. Binocular Disparity Why don’t we see double vision?

21. Binocular Disparity Why don’t we see double vision? Images with a small enough disparity are fused into a single image