prime35mmvintage
SMC Pentax-A 50mm f/1.4
Pentax · 1984-1989
Pentax's fast 50mm with program mode compatibility. The 'A' aperture setting enables automatic exposure control while retaining full manual capability. Excellent optics with premium build.
Known for
- Low light photography
- Portraits
- Program mode use
- Available light
Considerations
- Some vignetting wide open
- More expensive than f/1.7
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: Neutral, accurate
Common Issues
- Focus ring stiffness
- Aperture blade oil
Buying Guide
Common A-series fast 50. Check aperture operation. Good value for program-capable fast prime.
Specifications
MountPentax K
Focal Length50mm
Max Aperturef/1.4
Min Aperturef/22
Aperture Blades8
Min Focus0.45m
Filter Size49mm
Weight235g
Optical Design
FormulaDouble Gauss
Elements7
Groups6
CoatingSMC (Pentax)
Pricing
£60 - £120
Typical used price
Mint: ~£160
A-series fast 50 pricing
Adapts To
Sony EFujifilm XCanon RFMicro Four Thirds
Compatible Cameras
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Last verified: Jan 2026Report an error