Making Cross-Eyed 3D with One Camera

digital ed wrote:

First, please correct me if I am wrong.

When our eyes focus on a close object I believe their focus converges on the object. This would be the same as if when taking a stereo image of a close object the object is centered in the first photo and when the camera is moved to the second photo the object is re-centered by panning the camera. Would keeping the object centered in both left and right photos correct for the mis-centering of the resulting images? I can do this with a DSLR and you might not be able to do this with a fixed lens stereo camera.

One problem with panning is perspective warp of the lens when pointing the camera at the object. However, that can be somewhat fixed through alignment in Stereomaker. Another issue is that the lens will "see" more of the view when pointed left or right, than straight on causing some distortion and need for cropping. Certainly not recommended for objects beyond 3 feet. Another issue with panning is that it places objects beyond the main object in the wrong viewing plane. When our eyes focus on near objects, the objects beyond that object are ignored. But in an image that has a long depth of field, the objects in the background are not ignored and will appear crossed over the center viewing plane. For macro, though, it might work and possibly give a more rounded effect to the object, and it would place the object at the stereo window. BUT, you must make sure objects beyond the focused object are not visible. Best way to explain this is to draw two camera lenses on paper spaced eye length apart. Drawing lines straight out will show you that the lines never cross. Therefore, when viewing the objects, our eyes will force the closer objects to converge and the further objects less so giving correct depth. But now draw two camera lens focused on a near object centered. Note that the lines of sight cross at the object into the wrong camera plane for each eye for distant objects. Our eyes when focused on far objects must not cross the center plane, and for each object inbetween the same is true. Does that make sense?