Lens · prime
SMC Pentax 50mm f/1.2
Pentax · 1975-1984
Rare35mm
Pentax's first K-mount f/1.2 standard lens. Ultra-fast aperture for extreme low light and creative shallow depth of field. SMC Pentax 50mm f/1.2: 7 elements in 6 groups, 8 aperture blades, 0.45m minimum focus, 52mm filter thread, 385g.
- Focal length
- 50mm
- Max aperture
- f/1.2
- Mount
- Pentax K
- Format
- 35mm
- Elements / groups
- 7 / 6
Known for
- Ultra-low light
- Creative shallow DOF
- Character portraits
Considerations
- Soft wide open
- Heavy vignetting at f/1.2
Optical characteristics
Silverlog's editorial rating: our own judgement, not measured data.
Sharpness (wide)3, level 3 of 5
Sharpness (stopped)5, level 5 of 5
Contrast4, level 4 of 5
Flare resistance5, level 5 of 5
CA control4, level 4 of 5
Vignetting control3, level 3 of 5
Distortion control5, level 5 of 5
Bokeh: Legendary extreme blur
Rendering: Unique f/1.2 character
Colour: Warm, atmospheric
Silverlog's editorial rating, 1 to 5; five is best. Not lab-measured.
Common issues
- Focus ring stiffness
- Oil on blades
- Haze
Buying guide
Check all elements for haze. Test aperture operation.
Specifications
| Mount | Pentax K |
| Focal Length | 50mm |
| Max Aperture | f/1.2 |
| Min Aperture | f/22 |
| Aperture Blades | 8 |
| Min Focus | 0.45m |
| Filter Size | 52mm |
| Weight | 385g |
Optical design
| Formula | Double Gauss |
| Elements | 7 |
| Groups | 6 |
| Coating | SMC (Pentax) |
Pricing
- Typical used price
- £300 - £600
- Mint
- ~£800
Indicative, no dated source.