Specification of LOMO OKS5-250-1 optical block
The OKS5-250-1 lens is purposed for usual film shots.
| Manufacturer | NPO "EKRAN" | |
| Lens system | - | |
| Focal length | f' | 250.0 mm |
| Angle of view | 2ω' | 6°12' |
| Effective relative aperture | f:nэ | 1:2.9 |
| Lens length | Σd | 110.6 mm |
| Front focal length | S | - |
| Back focal length | S' | 151.5 mm |
| Flange focal distance | Z | - |
| Block length | B | 230 mm |
| Block max. diameter | D | 135 mm |
| Rear diameter | D' | - |
| Front element diameter | d1 | 89.5 mm |
| Rear element diameter | d2 | 56.5 mm |
| Mount thread | - | |
| Distance from rear end of the housing to the focal plane |
l | - |
| Aperture blades quantity | ? | |
| Frame size | 16x22 mm | |
| Weight | 3.1 kg |
