My dad has old canon lenses from the 70s and I was thinking I’d get him a DSLR, specifically the Canon Digital Rebel XTi. I heard that the old lenses do fit the EOS series but I have no idea if that’s true or not. Is there anyway I can tell by looking at the lenses themselves? A model number or something?
If you have old manual focus Canon Lenses from the 70’s, they won’t fit a modern EOS digital or film autofocus SLR.
When Canon moved to autofocus, they totally changed the mount so that the older manual focus lenses won’t mount and meter.
There are adapters, but they have severe limitations, like an inability to focus to infinity and no metering.
So, forget the old lenses; they aren’t going to work. Just get him the camera with a new lens and look forward.

No they don’t. The new ones communicate electronically with the camera–the old one has prongs (etc) thus mechanically worked with the old bodies.
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