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Comparison

Olympus OM-System Zuiko Auto-S 50mm f/1.4 vs Pentax SMC Pentax-M 50mm f/1.4

The Olympus OM-System Zuiko Auto-S 50mm f/1.4 is a 50mm f/1.4 Olympus OM lens made 1972-1980s, valued at $70 to $280 used. The Pentax SMC Pentax-M 50mm f/1.4 is a 50mm f/1.4 Pentax K lens made 1977-1984, valued at $60 to $210 used.

Specifications side by side

Olympus OM-System Zuiko Auto-S 50mm f/1.4 and Pentax SMC Pentax-M 50mm f/1.4 specifications compared
SpecificationOlympus OM-System Zuiko Auto-S 50mm f/1.4Pentax SMC Pentax-M 50mm f/1.4
Focal length50 mm50 mm
Maximum aperturef/1.4f/1.4
Native mountOlympus OMPentax K
Production years1972-1980s1977-1984
Optical design7 elements / 6 groups, Double Gauss7 elements / 6 groups, Double Gauss
Typical used value$130$110
Value range$70 to $280$60 to $210
Adapts toSony E, Fuji X, MFT, Canon RF, Nikon Z, L-mountSony E, Fuji X, MFT, Canon RF, Nikon Z, L-mount

What actually differs

  • Both open to f/1.4, so neither has a speed advantage.
  • The Pentax SMC Pentax-M 50mm f/1.4 is cheaper. Typical used value is $110 against $130, a gap of $20. Ranges: $60 to $210 versus $70 to $280.
  • Both are 50mm lenses, so framing is identical on the same sensor.
  • The Olympus OM-System Zuiko Auto-S 50mm f/1.4 is the older design; production began around 1972 against 1977 for the Pentax SMC Pentax-M 50mm f/1.4 (1972-1980s versus 1977-1984).
  • They use different mounts, Olympus OM and Pentax K, so each needs its own adapter. Both reach infinity on mirrorless bodies with a plain mechanical adapter.
  • Both use 7 elements in 6 groups.

Which one to buy

On the catalog data the Pentax SMC Pentax-M 50mm f/1.4 wins on the $20 lower typical price, and the Olympus OM-System Zuiko Auto-S 50mm f/1.4 gives up nothing measurable in return except its own rendering, described below. Condition and variant matter more than the spec sheet at these prices.

Minimum focus distance, weight, and measured sharpness are not in the catalog, so this comparison does not claim anything about them.

Full reference pages

Mount references: Olympus OM and Pentax K