| abstract |
In a single lens reflex camera a viewfinder contains an eye-piece facing the exit surface of a roof type pentagonal prism. The eye-piece includes, from the pentagonal prism end, a positive lens and a negative meniscus lens slightly spaced from the positive lens. A concave surface on the positive lens faces the pentagonal prism. The positive lens is composed of a plastic synthetic resin, letting R1, R2, R3 and R4 denote the radii of curvature of the lens surface of the eye-piece in that order from the pentagonal prism and f denote the composite focal length of the eye-piece, the following inequalities are satisfied: <IMAGE> <IMAGE> |