Systems and methods for improved focus tracking using blocking structures

Systems and methods disclosed herein include an optical blocking structure that may include a frame defining an aperture, first and second elongate structural members each comprising first and second ends such that the first and second elongate structural members may be connected at their first ends to opposite sides of the aperture, and further such that the first and second elongate structural members may extend from the frame parallel to and in the same direction as one another; and an optically opaque blocking member positioned to extend between the respective second ends of the first and second blocking members.