Spencer Buffalo Microscope The Spencer Buffalo Microscope was produced around 1940th. The optics is not the very best (especially the eyepiece), as chromatic abberations are visible. But it is clean and the instrument is a very good backup scope. You can find lots of information about Spencer microscopes on Steve Neeley's excellent website. I sold the Spencer microscope in 2004. Spencer microscope specifications: two Spencer achromatic objectives: 44x N.A. 0.65 and 95x N.A. 1.25 (oil immersion) standard Abbe condenser N.A. 1.25 with iris aperture diaphragm 6x eyepiece ('PLANOSCOPIC') plano-concave mirror mechanical stage coarse and fine focus controls condenser focusing knob