twin-lens reflex
Photography
noun
A camera with two lenses with equal focal length (typically one above the other), of which one is the taking lens, and the other projects the image via a mirror to a viewfinder; also attributive; abbreviated TLR.
- The advantage of this design is that the photographer sees (almost) the same view that the camera records, without the blacking out during exposure that occurs with a single-lens reflex..
Origin
Early 20th century; earliest use found in British Journal Photography.