Link to CZJ 75/1.5 gallery and gallery

R-Biotar, R for Roentgen. R-Biotar lenses were designed for x-ray photography. "R-BIOTAR 1932, Willy Merte, Zeiss. This was a high aperture narrow angle lens that was a variant of the Petzcal lens".

The first R-Biotar was 55mm f0.85, first made in the 1930's. Kodak adapted an f1 for cinematography many decades before Stanley Kubrick used a Zeiss 50mm f0.7 to make the movie Barry Lyndon. Kubrick's could also be used as 36mm f0.7 by means of an enlarger adapter. Leni Riefenstahl may have burned her images a bit dark in order to saturate with r-biotar, turning weakness to strength. R-Biotar, slightly more than biotar, can be difficult to saturate and color balance. I have heard that color balance shifts with aperture.

This Zeiss R-Biotar 75mm f1.5 M42 is the only R-Biotar shown on the internet which can be mounted on a still camera, is it not? Hmmm.