Specification of LOMO OKS7-28-1 lens (2/28mm)
The OKS7-28-1 lens has extended back focal length of 32 mm. Optical construction is complex system consisting of 9 elements grouped into 7 components. Image quality corresponds to early OKS4-28-1 lens, but OKS7-28-1 lens has longer back focal length.
| Manufacturer | NPO "EKRAN" | |
| Lens system | - | |
| Focal length |
f' | 28.0 mm |
| Angle of view | 2ω' | 51°50' |
| Effective relative aperture | f:nэ | 1:2.3 |
| Lens length | Σd | 43.3 mm |
| Front focal length | S | - |
| Back focal length | S' | 31.5 mm |
| Flange focal distance | Z | 41 mm |
| Block length | B | 45 mm |
| Block max. diameter | D | 45 mm |
| Rear diameter | D' | SpM 33x0.75 |
| Front element diameter | d1 | 31 mm |
| Rear element diameter | d2 | 18.5 mm |
| Mount thread | SpM33x0.75 cl 2a | |
| Distance from rear end of the housing to the focal plane |
l | 32.5 mm |
| Aperture blades quantity | 12 ? | |
| Frame size | 16x22 mm | |
| Weight | 130 g |
