prime35mmvintage
SMC Pentax-M 50mm f/2
Pentax · 1979-1985
Pentax's most compact 50mm lens. The f/2 aperture offers a middle ground between the f/1.7 and f/1.4 versions. Extremely light and small.
Known for
- General photography
- Travel
- Compact kit
- Learning
Considerations
- Slower than f/1.7
- Some versions have plastic parts
Optical Characteristics
Sharpness (wide)4/5
Sharpness (stopped)5/5
Contrast5/5
Flare Resistance5/5
CA Control4/5
Vignetting Control4/5
Distortion Control5/5
Bokeh: Pleasant rendering
Rendering: Clean, modern
Color: Neutral
Common Issues
- Focus ring wear
- Plastic aperture ring on some
Buying Guide
Less common than f/1.7. Check for metal vs plastic aperture ring. Good compact option.
Specifications
MountPentax K
Focal Length50mm
Max Aperturef/2
Min Aperturef/22
Aperture Blades6
Min Focus0.45m
Filter Size49mm
Weight155g
Optical Design
FormulaDouble Gauss
Elements5
Groups5
CoatingSMC (Pentax)
Pricing
£35 - £70
Typical used price
Mint: ~£100
Budget 50mm option
Adapts To
Sony EFujifilm XCanon RFMicro Four Thirds
Compatible Cameras
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Last verified: Jan 2026Report an error