Tamron 500mm Reflex Lens 騰龍500mm反射鏡頭

I bought a used Tamron 500mm f/8 mirror reflex lens last year. This kind of mirror reflective lens was produced in the 70s when I was learning film photography. It was created for photographer shooting with a longer focal length but in a compact size and light weight. However, this kind of reflective lens dropped out in favor in the 90s.