Lens · macro
SMC Pentax-M 50mm f/4 Macro
Pentax · 1977-1984
Discontinued35mm
Compact macro lens. Reaches 0.45x, just short of 1:2, without extension tubes. SMC Pentax-M 50mm f/4 Macro: 4 elements in 3 groups, 5 aperture blades, 0.23m minimum focus, 49mm filter thread, 160g.
- Focal length
- 50mm
- Max aperture
- f/4
- Mount
- Pentax K
- Format
- 35mm
- Elements / groups
- 4 / 3
Known for
- Macro
- Product photography
- Copy work
Considerations
- Slow aperture
- Just under 1:2 without extension
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 | 50mm |
| Max Aperture | f/4 |
| Min Aperture | f/32 |
| Aperture Blades | 5 |
| Min Focus | 0.23m |
| Filter Size | 49mm |
| Weight | 160g |
Optical design
| Formula | Double Gauss |
| Elements | 4 |
| Groups | 3 |
| Coating | SMC (Pentax) |
Pricing
- Typical used price
- £70 - £130
- Mint
- ~£180
Indicative, no dated source.