Darkfield condenser.
Substage polarizing filter (polarizer). Arrow points to the Nicol prism
Substage aperture disc. Apertures are 4, 6, 8, and 10mm diameter. Arm (arrow) holds the wheel in detent.
DF condenser in position (arrow).
Polarized light microscopy (PLM) setup: A: Polarizer; B: Analyzer
Aperture disc in position.
The second polarizing Nicol prism (analyzer; B) is inserted between the objective (A) and body tube.
Components of the PLM setup: Analyzer and Polarizer. Both are Nicol prisms.