25.4mm Diameter Microscope Darkfield and Oblique Illumination Set

Description

Almost any bright field laboratory microscope can be easily converted for use with dark field illumination if under condenser is a filter holder.
The available filters are shown in the attached picture,  please notice above every filter is shown the diameter of the center stop. Material 1.4mm Delrin.
The center stops are from 6.5 millimeters to 19 millimeters.
The overall diameter is made to be inserted in a condenser tray featuring a 25.4mm insertion diameter. This set is custom made to fit a large range of scopes and it is not a brand name.
In oblique illumination, direct light is restricted to a single azimuth, striking the specimen from only one direction rather than bathing it with an even distribution of light. The net effect is to reveal details in pseudo-relief to produce a shadowed effect on the side opposite the light source and bright specimen highlights on the side nearest the illuminator. You are bidding for a set of eight filters as is shown in the attached picture.