prime35mmvintage
SMC Pentax-K 50mm f/1.4
Pentax · 1975-1977
The original Pentax K-mount fast 50mm. Premium build quality from the first K-series. Slightly heavier than the later M version but with superior fit and finish.
Known for
- Low light photography
- Portraits
- Available light
- Premium quality
Considerations
- Heavier than M version
- More expensive
Optical Characteristics
Sharpness (wide)4/5
Sharpness (stopped)5/5
Contrast5/5
Flare Resistance5/5
CA Control4/5
Vignetting Control3/5
Distortion Control5/5
Bokeh: Smooth 8-blade rendering
Rendering: Classic fast 50 character
Color: Warm, pleasing
Common Issues
- Focus ring stiffness
- Oil on aperture blades
Buying Guide
Premium K-series lens. Check aperture operation. Worth seeking out for the superior build quality.
Specifications
MountPentax K
Focal Length50mm
Max Aperturef/1.4
Min Aperturef/22
Aperture Blades8
Min Focus0.45m
Filter Size49mm
Weight275g
Optical Design
FormulaDouble Gauss
Elements7
Groups6
CoatingSMC (Pentax)
Pricing
£80 - £150
Typical used price
Mint: ~£200
Premium K-series pricing
Adapts To
Sony EFujifilm XCanon RFMicro Four Thirds
Compatible Cameras
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Last verified: Jan 2026Report an error