Lumitar 5cm f1.5

Lens Data

Lens Unit

Lens Photo

レンズ構成:不明(5群8枚 ゾナー・ガウス折衷型と推定

Production year: c1942
Composition: unknown (est. 5group 8lenses
    hybrid Sonnar and Gauss type)

Lens Impression


Up to now, this lens is a real unidentified lens of its origin, but only known to have been equipped on X-ray indirect photography cameras made by Nippon Kogaku Kikai Lab. which made their first camera in 1942.
The outlook of this lens is very similar or almost same to the Zeiss Sonnar f1.5 which was regarded as the highest as an indirect photographing lens at that time. The lens composition is also unknown , so I made a effort to disassembe the lens as much as possible, and reached to the assumption that the composition should be a hybrid type of Sonnar in front and Gauss in rear.
As it is a lens for X-ray photo, it has no diaphragm nor helicoid. The original position used in very dark room, the light control inside the lens is not enough as other normal lenses, it gives me more flare in full open aperture.

 Photos with Lumitar 5cm f1.5

After I serched and checked some reports in the library of the Tokyo Metropolitan Museum of Photography, I made a trial of this lens while walking in the direction of Daikanyama. It should have been a very dazzling time for this lens which was born dedicated to darkness. It seems that the depiction of the surroundings is almost wandering in the images taken, as if the lens felt dizzy under the sunshine.