Patent ID: 8331018

Claim:
An optical system for merging a first and a second partial image beam into a resultant image beam in an optical instrument, wherein the first and second partial image beam both emanate from a specimen, said optical system comprising a stop arrangement provided with: at least one first movable stop element for the first partial image beam; at least one second movable stop element for the second partial image beam; wherein said first and second stop elements each comprise at least one stop region adapted to be brought into a working position with the first or second partial image beam by movement of the respective first or second stop element in order to modify the areal proportion of the respective first or second partial image beam in the resultant image beam; and a movably arranged connecting element for connecting and moving the two stop elements; wherein the stop arrangement is adapted to be brought by a first movement into a first set of first and second configurations in that the first and the second stop element assume a respective first position and wherein a rotary movement of the connecting element in this first configuration around a first axis of rotation increases the areal proportion of the first partial image beam in the resultant image beam and decreases the areal proportion of the second partial image beam in the resultant image beam; and the stop arrangement can be brought by a second movement that is a rotation of the connecting element about a second axis of rotation into a second set of first, second, third, and fourth configurations of the connecting element bringing the stop elements into the first, second, third, and fourth positions, respectively.