The Tamron SP 300mm f/5.6 (specifically the Model 54B) is a manual-focus telephoto prime lens part of the Adaptall-2 system, which allows it to be used on Minolta MD or Sony/Minolta A-mount cameras with the appropriate adapter.
It is highly regarded as a specialized "tele-macro" lens because it can focus as close as 1.4 meters (55.1 inches), achieving a 1:3.3 macro magnification ratio without additional accessories.
Core Specifications:
Optical Construction: 6 elements in 5 groups, including a "spherical aberration compensator group" for improved close-up sharpness.
Aperture Range: f/5.6 to f/32 with 8 or 9 diaphragm blades (depending on the specific production batch).
Physical Build: All-metal body weighing approximately 610g (21.5 oz) and measuring about 163.5mm in length.
Filter Size: 58mm.
Features: Built-in retractable lens hood and an optional tripod mounting ring.
