The simplest and least expensive method to add darkfield capabilities to a light microscope is to add a simple darkfield patch stop to the condenser, to block the central area of the aperture diaphragm from receiving light, thereby creating the hollow cone of illumination necessary for darkfield. In many scopes, the design of the condenser is such that a filter slot or carrier placed at the bottom of the condenser is physically close enough to the aperture diaphragm for a patch stop placed within the slot or carrier to provide effective darkfield for low-power objectives (4x – 20x). The design of the BH2 condensers complicate things a little bit, since the internal aperture diaphragm is too far removed from the bottom surface of the condenser mounting dovetail for a slot or carrier to be effective for darkfield. Fortunately, with the advent of 3D printing, it is a simple matter to fabricate an insert compatible with the BH2 condensers that, when pushed up into the bottom bore of the condenser, will position a patch stop in the appropriate location for effective darkfield.