Lens · macro
SMC Pentax-A 100mm f/2.8 Macro
Pentax · 1985-1989
Discontinued35mm
SMC Pentax-A 100mm f/2.8 Macro: 7 elements in 7 groups, 8 aperture blades, 0.31m minimum focus, 58mm filter thread, 470g.
- Focal length
- 100mm
- Max aperture
- f/2.8
- Mount
- Pentax K
- Format
- 35mm
- Elements / groups
- 7 / 7
Known for
- Macro
- Portraits
- Product photography
Considerations
- Long focus throw
- Heavy for macro work
Optical characteristics
Silverlog's editorial rating: our own judgement, not measured data.
Sharpness (wide)5, level 5 of 5
Sharpness (stopped)5, level 5 of 5
Contrast5, level 5 of 5
Flare resistance4, level 4 of 5
CA control3, level 3 of 5
Vignetting control3, level 3 of 5
Distortion control4, level 4 of 5
Silverlog's editorial rating, 1 to 5; five is best. Not lab-measured.
Common issues
- Check for fungus
- Inspect aperture blades
Buying guide
Check aperture operation, focus smoothness and the condition of the glass and coatings.
Specifications
| Mount | Pentax K |
| Focal Length | 100mm |
| Max Aperture | f/2.8 |
| Min Aperture | f/22 |
| Aperture Blades | 8 |
| Min Focus | 0.31m |
| Filter Size | 58mm |
| Weight | 470g |
Optical design
| Formula | Telephoto |
| Elements | 7 |
| Groups | 7 |
| Coating | SMC (Pentax) |
Pricing
- Typical used price
- £200 - £350
- Mint
- ~£450
Indicative, no dated source.