Patent ID: 8619252

Claim:
A microscope, comprising: an objective; and a light intensity measuring unit for measuring an intensity of light emitted from the microscope, the light intensity measuring unit comprising: an aperture stop arranged on or close to a plane corresponding to a back focal plane of the objective during observation; a field stop arranged on or close to a plane corresponding to a front focal plane of the objective during observation; at least one measurement lens arranged between the aperture stop and the field stop; an interface for attachment to the microscope; and a photodetector for measuring a light intensity, wherein: the field stop is positioned on or close to a front focal plane of the at least one measurement lens, and positioned between the at least one measurement lens and the photodetector; the aperture stop is positioned on or close to a back focal plane of the at least one measurement lens; and the light intensity measuring unit is installed in the microscope such that light equivalent to light incident on the objective during observation enters the aperture stop.