Specification of DISTAGON 1.2/25MM
It seems to be a lens for 16mm film, but my reference book states that it is for 35mm film.
| Manufacturer | "OPTON" (Germany) | |
| Lens system | - | |
| Focal length | f' | 25.9 mm |
| Angle of view | 2ω' | 57°06' |
| Effective relative aperture | f:nэ | 1:1.4 |
| Lens length | Σd | 78 mm |
| Front focal length | S | - |
| Back focal length | S' | 27.2 mm |
| Flange focal distance | Z | - |
| Block length | B | 88 mm |
| Block max. diameter | D | 76 mm |
| Rear diameter | D' | 41 mm |
| Front element diameter | d1 | 47.5 mm |
| Rear element diameter | d2 | 27.0 mm |
| Mount thread | - | |
| Distance from rear end of the housing to the focal plane |
l | 26.2 mm |
| Aperture blades quantity | ? | |
| Frame size | 16x22 mm | |
| Weight | 550 g |
