Hello, I am hoping to get some answers here regarding a lens for my Rebel xti. I am VERY new at this! My dad has a Tamron lens from about 20 years ago, he never used. I want to know if it can be used on my Rebel xti? It is a Tamron 80-120 mm F13.8-4 CF Tele-Macro Zoom Adaptall 2 mount

I am assuming it needs and adapter if it ill work at all. Also, what kind of lens is this used for?

Thanks in advance!

You would need an adapter. But even if you can find one, I wouldn't bother. A new lens will be much, much better. That lens probably doesn't have the optical quality of even current inexpensive lenses. And you won't have auto focus with it. The only reason to use an adapter for lenses on an EOS body is if you have a really good specialty lens you want to use. I know guys who use some really expensive non-Canon manual focus macro lenses with their EOS bodies. But that's not the same as paying for an adapter just so you can use an old lens that's laying around the house. Better to invest your money in a new lens.