Carl Zeiss Jena R-Biotar 100mm f/0.73
| Company | Carl Zeiss Jena |
| Country | East-Germany |
| Year of manufacture | 1965 |
| Type | X-ray |
| Focal length | 100mm |
| Aperture | f/0.73 |
| Optics |  |
| Image circle at infinity |  |
Notes: The R-Biotar 100mm f/0.73 lens was made to be on the “Röntgenkamera 70” (RK 70) also called “Jena 70” which was used to take fluorescent screen photographs, also called fluorographs. The markings on the lens β’1/6,3 means magnification of 1:6.3 when using 70mm film, because the β is the symbol for medium size film 70mm wide. The lens was developed by VEB Carl Zeiss, Jena from around 1959 to 1964. Prof. Dr. Harry Zöllner, and Fritz Disep, who worked at various project including X-ray lenses and systems at this time, are the inventors of this lens.
