Abstract

The Polaroid Spectra camera contains an unusual telescopic viewfinder comprised of injection-molded components and glass mirrors. The camera’s geometry required a radical departure from the reversed Galilean form typically found in inexpensive cameras. The result is a viewfinder which is over 150 mm in length, has an eye relief of 17 mm, and a magnification of 0.5, covers a full field in excess of 54°, and yet presents a cross section at the front of the camera of <18 × 12 mm. The Spectra's reverse telephoto design includes seven lenses, five aspheric surfaces, and two prisms as well as a four-mirror erecting system. High-volume manufacturing techniques required a design which allows for automated assembly and testing.

© 1987 Optical Society of America