Tamron 300mm f/5.6 (CT-300) - Tamron Adaptall Mount

The Tamron 300mm f/5.6 (CT-300) is a manual-focus telephoto prime lens featuring the Adaptall mount system. It was designed to provide a significant reach in a relatively slim and portable package. While slower than professional f/2.8 or f/4 alternatives, its f/5.6 aperture allows for a much smaller filter diameter and lower weight, making it suitable for handheld nature or sports photography in good light. The all-metal barrel reflects the high build standards of Tamron's early interchangeable mount lenses. Prospective buyers should check the internal optics for fungus, particularly in the larger rear elements. The manual focus ring has a very long throw for precision; SDS ensures this movement is consistent and not hampered by dried grease. We also check the aperture linkage for correct communication with the Adaptall adapter. Ensure the tripod collar, if included, locks securely, as these are essential for stable shooting at this focal length.