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SMC Pentax-M 120mm f/2.8

Pentax · 1977-1985

Pentax's unique 120mm telephoto. The focal length sits between 85mm and 135mm, offering excellent portrait compression with closer focusing than longer telephotos. Highly regarded by portrait photographers.

Known for

  • Portraits
  • Headshots
  • Events
  • Unique focal length

Considerations

  • Uncommon focal length
  • f/2.8 limits low light

Optical Characteristics

Sharpness (wide)
4/5
Sharpness (stopped)
5/5
Contrast
5/5
Flare Resistance
5/5
CA Control
4/5
Vignetting Control
4/5
Distortion Control
5/5

Bokeh: Beautiful 8-blade bokeh

Rendering: Excellent compression

Color: Neutral, accurate

Common Issues

  • Focus ring stiffness
  • Less common than 85mm/135mm

Buying Guide

Less common than other focal lengths but highly regarded. Check focus smoothness. Worth seeking out.

Specifications

MountPentax K
Focal Length120mm
Max Aperturef/2.8
Min Aperturef/32
Aperture Blades8
Min Focus1.2m
Filter Size49mm
Weight270g

Optical Design

FormulaTelephoto
Elements5
Groups5
CoatingSMC (Pentax)

Pricing

£80 - £150

Typical used price

Mint: ~£200

Premium for unique focal length

Adapts To

Sony EFujifilm XCanon RFMicro Four Thirds

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Last verified: Jan 2026Report an error
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