Eos Xsi
Why is my Tamron 75-300 mm lens will not mount on my Canon EOS Xsi?

I recently bought a new camera for my Canon Xsi and it seems as if no attach to the body. Do I need to purchase some type of converter lenses? Thanks!

The cameras have lenses of specific frames, so Canon only have a Canon camera lens mount specific (and distinguishes between the Canon EF and EF-S and manual focus mounts). Pentax cameras have goals Pentax mount, etc. Therefore, it is likely that the Tamron lens you have is on Mount wrong if it does not fit your Canon. Check the box that was subject to confirmation and / or change of the store where purchased. And if it is a manual focus lens for Canon Tamron note that the Canon manual focus lenses are completely different lenses Canon Auto Focus (EF and EF-S).