The Triplet 78 mm f/ 2.8 (Russian: Триплет 2,8/78) is a projection lens for slide projectors.
The rear flange is about 60 mm long, so it can be mounted on any camera. The lens has neither diaphragm nor helicoid. A third party helicoid can be attached for a convenient focusing. The lens delivers soft images and is suitable for art photography.