Patent ID: 7777941

Claim:
A Greenough-type stereomicroscope comprising: a first monocular microscope defining a first beam path and including a first magnification system defining a first optical axis, a first optical element having a first optically effective diameter, and a first observation unit disposed in the first beam path and configured to convey light of the first beam path forming a first partial image of a 3-dimensional image to a first eye of a user; and a second monocular microscope defining a second beam path and including a second magnification system defining a second optical axis disposed at a convergence angle to the first optical axis, a second optical element corresponding to the first optical element and having a second optically effective diameter, and a second observation unit disposed in the second beam path and configured to convey light of the second beam path forming a second partial image of the 3-dimensional image to a second eye of the user, wherein the first and second magnification systems are configured to produce an equal magnification with one another that is synchronously variable, wherein the first optical element has a different optically effective diameter than the corresponding second optical element such that the first partial image and second partial image have different resolution and depth of field, and wherein a first numerical aperture of the first microscope is greater than a sine of the convergence semi-angle.