Vivitar — 135mm f/3.5 budget telephoto prime, widely sold across vintage SLR mounts
Vivitar's 135mm f/3.5 was one of the brand's most widely sold telephoto primes, a budget alternative to first-party 135mm lenses that became a fixture of camera-store shelves through the 1970s and into the 1980s. It was often bundled with entry-level SLR kits as an add-on telephoto.
It is a manual-focus prime with an automatic diaphragm for open-aperture metering, offered at the modest f/3.5 maximum aperture typical of budget telephoto primes of the era. Vivitar manufactured it in enormous numbers across nearly every interchangeable SLR lens mount sold at the time.
Optically it is a simple, solid performer rather than a showcase lens, sharp enough stopped down for portraits and general telephoto work but unremarkable wide open. Its main appeal was always affordability and availability rather than optical distinction.
Given how widely it was sold, clean examples remain easy and cheap to find secondhand across almost any vintage SLR mount. Check the focus helicoid for smooth travel, confirm the aperture blades are free of oil, and verify the exact mount fitted before buying.