Tamron 28-135mm f/4-4.5 (28A) - Tamron Adaptall-2 Mount

The Tamron 28-135mm f/4-4.5 (model 28A) is a high-performance manual-focus zoom lens from the Adaptall-2 era. Offering a versatile range from wide-angle to telephoto, it was designed as a high-quality 'one-lens' solution for film photographers. It features a sophisticated optical design for its time, maintaining a relatively fast aperture throughout the zoom range. The lens is solidly built with a metal barrel and high-quality glass, typical of the premium Adaptall-2 line. For used buyers, the primary concern is the weight of the optics causing zoom creep when the lens is pointed vertically. The zoom/focus action should be checked for smoothness across the entire range. SDS examines the internal elements for any signs of coating degradation or fungus. Additionally, the aperture mechanism should be tested at both ends of the zoom to ensure the variable aperture linkage is functioning correctly with the Adaptall mount.