I picked up this lens cheap at Belleville Flea Market.
It is not so heavy for its size, and is rated f:8, 500mm focal length.
Seem to be at least 4 lens groups within.
The mount is adaptable, accepts the outer portion of T Mount adapters.
Manual focus from about 30 feet to infinity.
"Preset" type of aperture, with open/close control ring.
There is some dirt trapped within on inner glass surfaces, but lens proved difficult to disassemble, so I decided to test the lens as is.
I mounted it to a Pentax K100 D digital body and took it outside.
Subjects were mostly across the street or in neighboring yards, distances between 30 feet and 150 feet.
I shot these at ASA 800 setting, Aperture Priority mode.
Lens and camera were hand held, no tripod, with "Anti-Shake" function on the body switched on.
Some exposure compensation was needed, but lens performed better than expected.

Please click on thumbnails to see enlarged.
All images are Copyright 2014 E.J.Kowalski.