Check the listing for details. Polaroid Model PR-22 Exposure Meter, Analog Light Meter for Camera, UNTESTED. Condition: Used, Made in United States. Listed at 9.00 USD. Polaroid Model PR-22 Exposure Meter, manufactured by General Electric (GE) in the 1950s. This is a vintage light meter specifically designed for early Polaroid Land Cameras (like the Model 95, 100, or 800 series). The Dial: Unlike modern light meters that give you "f-stops" and "shutter speeds," this meter provides a single number from 1 to 8. These correspond to the proprietary exposure numbers found on the shutter dials of early Polaroid cameras. The Tech: It uses a selenium cell to measure light. Selenium cells are "self-powered" (they don't need batteries), but they often degrade over time. The Mount: The metal clip on the back allows it to slide into the accessory shoe (the "cold shoe") on top of the camera.