Asahi Pentax Super-Takumar 50mm f/1.4 vs Carl Zeiss Planar T* 50mm f/1.4 (C/Y)

What actually differs

• Both open to f/1.4, so neither has a speed advantage.
• The Asahi Pentax Super-Takumar 50mm f/1.4 is cheaper. Typical used value is $150 against $220, a gap of $70. Ranges: $80 to $400 versus $120 to $420.
• Both are 50mm lenses, so framing is identical on the same sensor.
• The Asahi Pentax Super-Takumar 50mm f/1.4 is the older design; production began around 1964 against 1975 for the Carl Zeiss Planar T* 50mm f/1.4 (C/Y) (1964-1971 versus 1975-2005).
• They use different mounts, M42 and Contax/Yashica, so each needs its own adapter. Both reach infinity on mirrorless bodies with a plain mechanical adapter.
• Construction differs: 8 elements in 6 groups for the Asahi Pentax Super-Takumar 50mm f/1.4, 7 elements in 6 groups for the Carl Zeiss Planar T* 50mm f/1.4 (C/Y).

Which one to buy

On the catalog data the Asahi Pentax Super-Takumar 50mm f/1.4 wins on the $70 lower typical price, and the Carl Zeiss Planar T* 50mm f/1.4 (C/Y) 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.