Carl Zeiss Planar T* 50mm f/1.4 (C/Y) vs Nikon Nikkor-S Auto 50mm f/1.4 (pre-AI)

What actually differs

• Both open to f/1.4, so neither has a speed advantage.
• The Nikon Nikkor-S Auto 50mm f/1.4 (pre-AI) is cheaper. Typical used value is $110 against $220, a gap of $110 (roughly 2x). Ranges: $60 to $220 versus $120 to $420.
• Both are 50mm lenses, so framing is identical on the same sensor.
• The Nikon Nikkor-S Auto 50mm f/1.4 (pre-AI) is the older design; production began around 1962 against 1975 for the Carl Zeiss Planar T* 50mm f/1.4 (C/Y) (1962-1974 versus 1975-2005).
• They use different mounts, Contax/Yashica and Nikon F (pre-AI), so each needs its own adapter. Both reach infinity on mirrorless bodies with a plain mechanical adapter.
• Construction differs: 7 elements in 6 groups for the Carl Zeiss Planar T* 50mm f/1.4 (C/Y), 7 elements in 5 groups for the Nikon Nikkor-S Auto 50mm f/1.4 (pre-AI).

Which one to buy

On the catalog data the Nikon Nikkor-S Auto 50mm f/1.4 (pre-AI) wins on the $110 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.