Your solution works in a geometric world, where light propagates in a perfect straight line of infinitesimally small width. That's not true in reality, where li

Your solution works in a geometric world, where light propagates in a perfect straight line of infinitesimally small width. That's not true in reality, where light propagates in an ever-expanding cone. More concretely, you can have two cameras photographing along different but parallel planes that do see each other.