The Polaroid Electric Eye 900 represents a major technological peak for the original roll film era. Introduced in 1960, it was the most advanced camera in the large-format line, featuring a fully automatic exposure system powered by a selenium photocell. Unlike earlier models where you had to manually set exposure values, the "Electric Eye" on the 900 automatically adjusted the aperture and shutter speed based on the lighting conditions. This was a high-end professional-tier camera, often characterized by its rugged build, high-quality lens, and a single-window viewfinder/rangefinder for easier focusing.