Lens · prime
Mamiya-Sekor C 90mm f/3.8
Mamiya · from 1974
Mamiya-Sekor C 90mm f/3.8: 7 elements in 5 groups, 77mm filter thread, 805g.
- Focal length
- 90mm
- Max aperture
- f/3.8
- Mount
- Mamiya RB
- Format
- 120
- Elements / groups
- 7 / 5
Known for
- Portraits
- Studio
- Product
- Fashion
Considerations
- Leaf shutter in the lens: cock the camera and lens shutters before mounting
Optical characteristics
Silverlog's editorial rating: our own judgement, not measured data.
Bokeh: Smooth, medium format depth
Rendering: Natural, medium contrast
Colour: Neutral
Silverlog's editorial rating, 1 to 5; five is best. Not lab-measured.
Versions
Sekor (original)
1970-1974
No C suffix; single-coated
7 elements in 6 groups, 705 g
Sekor C
C suffix after the aperture; multi-coated
7 elements in 5 groups, 805 g; introduced with the RB67 Pro-S in 1974
The original 1970 Sekor lens was single-coated (7 elements in 6 groups); the Sekor C version that followed in 1974 is multi-coated and uses 7 elements in 5 groups. The later K/L 90mm f/3.5 L is a different, floating-element design rather than a version of this lens.
Buying guide
Check the leaf shutter fires at all speeds, the aperture and focusing smoothness, and the condition of the glass.
Specifications
| Mount | Mamiya RB |
| Focal Length | 90mm |
| Max Aperture | f/3.8 |
| Min Aperture | f/32 |
| Filter Size | 77mm |
| Weight | 805g |
Optical design
| Formula | Planar |
| Elements | 7 |
| Groups | 5 |
| Coating | Multi-Coated |
Pricing
- Typical used price
- £150 - £300
- Mint
- ~£400
Indicative, no dated source.