Optics of the Smith and Beck compound microscope. A: Eye lens (plano-convex, dia=15mm, f=32mm). B: Eyepece field lens (plano-convex, dia=26mm, f=50mm). The eyepiece is of the Ramsden design with the convex surfaces facing the center of the eyepiece.
Objective lenses. A: High magnification non-immersion lens with tubelength correction collar. B: Low magnification lens showing separable lens tubes.
Low-magnification lens assembled.
Correction collar detail. "Uncovered" means that no coverslip or immersion oil is required for this objective.
The illuminating mirror has one parabolic surface. Diameter = 3.6cm.