A method and apparatus for generating three dimensional image information using a single imaging path having an associated field of view. Two images are selectively received through respective portions of the single imaging path, each portion having a perspective viewpoint within the field of view. The two images together are operable to represent three dimensional spatial attributes of objects within the field of view. To create a change in the representation of the three dimensional spatial attributes, an extent of the two portions of the imaging path are varied to cause the perspective viewpoints to change location. While varying the extent of the portions, compensating for changes in transmission allows an image intensity associated with each of the two images to be maintained at a generally uniform image intensity level.
