Three polarizing Strain Free (SF) objectives are included.  All are infinity corrected and 34 mm parfocal with standard RMS mounting threads.  The three objectives are those which were originally supplied with the AO 110/120 POLSTAR microscopes.  The objectives are 4X Plan Achromatic Catalog #1017 Strain Free, 10X Achromatic Catalog #1026 Strain Free, and 40X Achromatic Catalog #1891 Strain Free.  The 40X objective has a very high numerical aperture (directly related to resolving power) of 0.85. All the objectives are very clean, with clear glass free of dust, fungus, etc.  There is no delamination.

All essential lens surfaces are coated with AMERICOTE,  a patented antireflective lens coating system which decreases internal reflections, improves light transmission, and image contrast.    

All objectives are parcentered and parfocalized.  The objective turret is of ball bearing construction and rotates smoothly and clicks positively into place for each of the objectives.  There is room for a 4th objective which is currently protected by an AO dust cap.  

The 4-position objective turret contains a COMPENSATOR SLOT for insertion of the AO Cat 1886 1/4 wave mica plate or the Cat. 1887 Full Wave Plate (note:  these wave plates are not included in this auction).