Hello, This is really more of a question about a film camera of mine- Canon EOS A2, but I'm sure you guys can help me out. I have a this Sigma lens: http://allphotolenses.com/lenses/item/c_710.html - and I want to use it on my A2 (the lens says "for canon" on the connecting end of it...?) but as far as I can tell it wont attach without an adapter of some sort. I'm assuming it's made for an older film camera. Does any adapter like that exist? I'm not very experienced with different lenses/cameras so forgive my ignorance, but any help would be appreciated, thanks!