question

[reid506]

I have a Nikon D90. I also have an old 50mm lens from the 70s or 80s (it was my parents). I know it fits on the D90 because I've put it on there. I want to make sure I'm not damaging anything by using it. The auto focus doesn't work so I have to manually focus but I just want to make sure I'm not slowly damaging the D90. Thanks.

Reid

[candleman]

which lens is it exactly?

"Pre-Ai" lenses will mount to your camera, but it damages things by doing so.
the fact that it doesn't AF on your D90 has me worried.