Zeiss's generic 135mm f/3.5 — likely a Jena or West German telephoto without specific designation.
The Zeiss 135mm f/3.5 is a vintage telephoto prime in the Zeiss optical tradition. Without a specific mount designation, this is likely a Contax/Yashica (C/Y) mount version of the classic Zeiss 135mm Sonnar-formula telephoto. Confirm mount before purchase.
f/3.5 maximum aperture. 135mm focal length (full-frame). Zeiss Sonnar or Planar optical formula (classic portrait telephoto). Manual focus. Mount: confirm C/Y, Nikon F, M42, or other before purchase.
The Zeiss 135mm f/3.5 existed in multiple mount configurations across different eras. The C/Y (Contax/Yashica) mount version is most common for collector use and mirrorless adaptation. Verify specific mount from physical lens markings.
On the used market the Zeiss 135mm f/3.5 is a classic portrait telephoto prime. Condition checks: front element for marks, aperture blade condition, focus ring. CONFIRM MOUNT before purchase.