Tamron 35-70mm f/3.5 CF Macro (17A) - Tamron Adaptall-2 Mount

The Tamron 35-70mm f/3.5 CF Macro (model 17A) is a classic manual-focus zoom from the Adaptall-2 era. It features a constant f/3.5 maximum aperture, which provides a brighter viewfinder image and consistent exposure settings compared to variable-aperture zooms of the same period. The 'CF' designation stands for Continuous Focusing, allowing the lens to transition smoothly into macro mode at the 70mm end, reaching a reproduction ratio of 1:2.8. Its robust all-metal construction makes it a reliable choice for film enthusiasts or mirrorless users via adapters. On used examples, the zoom and focus rings should be checked for smooth, damped rotation; excessive 'zoom creep' is uncommon but can occur if the internal friction collars are worn. The Adaptall mount interface should be inspected for bent pins or loose connections. SDS checks the six-blade aperture diaphragm for oil contamination and ensures the 'Macro' range engagement remains positive and crisp.