Olympus PM-CB20 Exposure Control Unit, Microscope Controller

1x Olympus Co, PM-CB20 Exposure Control Unit, Microscope Controller

The control box for the Olympus PM-20 camera has a liquid crystal display
that permits user-controlled entry for such items as film size, ISO rating of film,
exposure adjust for unusual lighting conditions, reciprocity setting,
automatic ISO setting for DX coded film, double exposure capability, exposure lock,
bracketing exposure settings, color temperature accessory,
lighted frame for fluorescence, and several other variables.

The PM-20 has a built-in silicon photodiode system whose meter reads the central 30 percent of the field of view or,
using the spot meter lever, the central 1 percent of the field of view.
The automatic exposure meter reads the "live" image continuously until the shutter closes.
The PM-20 has a setting for fluorescence microscopy whose algorithm automatically
reduces the exposure time by 80 percent to prevent overexposure.