Lens · prime
SMC Pentax-A 28mm f/2.8
Pentax · 1984-1988
Vintage35mm
Pentax's A-series wide-angle with program mode compatibility. Optically the same as the later M version, with added automatic exposure capability. SMC Pentax-A 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
- Program mode use
- Landscapes
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.
Common issues
- Focus ring wear
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 | 170g |
Optical design
| Formula | Retrofocus |
| Elements | 7 |
| Groups | 7 |
| Coating | SMC (Pentax) |
Pricing
- Typical used price
- £45 - £90
- Mint
- ~£120
Indicative, no dated source.