I was thinking it might have something to do with the lens but I still have no idea since it is a Mamiya lens and I got it as a bundle from KEH.com.
The camera is a Mamiya 645E and the lens is a Mamiya-Sekor 80mm f/2.8 N. Is there anything about this lens/camera combo that causes it to not focus to infinity? I don't think it's even infinity unless infinity is actually pretty close. I live in an apartment building that used to have a fraternity house inbetween the other matching apartment building and I can't focus on things that are past the frat house, like trees. They look decently close with the split prism or even in focus but when I actually look at the sharpness of trees and anything else, nothing really LOOKS in focus. I have the diopter set to -1 though, could this have anything to do with it? I know that when you have lens adapters it can offset infinity focus or certain macro attachments but the diopter is the only thing I can think of. I haven't had a chance to really check out the negatives to see if I'm just hallucinating (I doubt it) but I have also managed to do what I could to get the infinity stuff in focus by stopping down to say f11 and by using the depth of field preview.
Thanks for any help you can give me!