Hi Stanycjw ,
Nice to hear from you again.
This is a Nikon 500mm F8 (Later Version ) .Its a fully Manual reflex lens and can adapt a Nikon Teleconverter (TC14B or TC 301 )
Its Super Sharp and one has to master the technique on handling one of this sweet little Chilli Padi in which anytime it can kill any of this Montrous tele photo lens (which I myself have it all before from 300mm to 600mm with AF-S VR 2 ) now sold to some of close buddies .
Many Pros always bring the issues on this Reflex lens for their weakness on Contrast ,BOKEH ( In Japanese )and Fix aperture .
But none has really spent much time on it neither mastering it as this are Special Purpose lens and not a everyday use lens .
For me its a everyday use lens and its always in my camera Bag .
I have owned a few of this Super Mirror lens from 350mm to 1600mm from Sony/Minolta , Nikon ,Tamron ,Vivitar (Solid Cat 1 )and Zeiss.
I have yet to know any one know how to appreciate a Reflex lens .
Since I am just a Amateur for the last 30 over years in which I am still learning new techniques from all the New software and New DSLR now .
Photography is all about Arts and Science combination and one have to master certain skills on certain lens and control of lighting too .
One also must have that inborn Creative Flare in them too but not just monkey follow monkey or just reading from margazine or reviews from those So Call Professional reviewers.
The One person That I have respected the Most is the Late Mr.Herbert Kepler and he is my mentor .
I have many young and older photographers (Close Buddies ) from all over the globe who uses Reflex lens and it all came out with very Nice Capture, superb sharpness from those Nature,Sports and Landscape photos .
Reflex lens is so compact and super sharp as one can stalk a birdie or a animal in their natural habitat as Big and Montrous Telephoto lens cannot do it .
My dear Friend if you do need any advice pls feel free to PM me .
I am a Retired Old but Young and trendy Looking man !!LOL!!!!!!!!!!!!!!!
Take more photos as photos create mood and beauty of this world every each day.
Cheers
OLdtimer