Albada type viewfinder for camera - uses two concave and one convex lens for viewing with third concave lens for range finder

摘要

An Albada viewfinder for a camera comprises two concave lenses (L1, L2) and a convex one (L3). The masking for field view in on the convex lens element. The viewfinder incorporates a rangefinder, with a separate concave lens (L1) and two associated mirrors. At least the perimeter surface of the lower mirror is transparent to let through radiation originating from the field mask and imaged on the second lens element.