SIMULTANEOUSLY OBSERVING A TRANSPARENT OBJECT FROM TWO DIRECTIONS

In order to simultaneously observe a transparent object from two directions, first and second beam paths containing first and second images from two directions are separated using a prism to reflect the second beam path yet pass the first beam path. The length of the second beam path is caused to be different from that of the first beam path. Then the first and second beam paths are combined so that the first and second images may be viewed simultaneously. The different beam path lengths result in the first and second images being formed at the same position. As a result, the images carried by the first and second beam paths, both passing through a single objective lens, may be viewed simultaneously at a single location.