Lens · prime
SMC Pentax-M 28mm f/2.8
Pentax · 1977-1982
Vintage35mm
Pentax's compact wide-angle lens. SMC Pentax-M 28mm f/2.8: 7 elements in 7 groups, 5 aperture blades, 0.3m minimum focus, 49mm filter thread, 170g.
- Focal length
- 28mm
- Max aperture
- f/2.8
- Mount
- Pentax K
- Format
- 35mm
- Elements / groups
- 7 / 7
Known for
- Travel photography
- Street photography
- Landscapes
- Architecture
Considerations
- 5 aperture blades
- f/2.8 limits low light
Optical characteristics
Silverlog's editorial rating: our own judgement, not measured data.
Sharpness (wide)4, level 4 of 5
Sharpness (stopped)5, level 5 of 5
Contrast5, level 5 of 5
Flare resistance5, level 5 of 5
CA control4, level 4 of 5
Vignetting control4, level 4 of 5
Distortion control4, level 4 of 5
Bokeh: Pleasant for wide angle
Rendering: Sharp, contrasty
Colour: Neutral
Silverlog's editorial rating, 1 to 5; five is best. Not lab-measured.
Versions
Version I
1977-1982
Silver ring on focusing ring
156g, slightly lighter
Version II
1982-1984
No silver ring
170g
Two versions produced, both 7 elements in 7 groups. The second version uses the optical design of the later A 28mm f/2.8 and lacks the silver ring.
Common issues
- Focus ring wear
- Dust in rear group
Buying guide
Check focus smoothness.
Specifications
| Mount | Pentax K |
| Focal Length | 28mm |
| Max Aperture | f/2.8 |
| Min Aperture | f/22 |
| Aperture Blades | 5 |
| Min Focus | 0.3m |
| Filter Size | 49mm |
| Weight | 156g |
Optical design
| Formula | Retrofocus |
| Elements | 7 |
| Groups | 7 |
| Coating | SMC (Pentax) |
Pricing
- Typical used price
- £40 - £80
- Mint
- ~£110
Indicative, no dated source.