You'll always have problems as a digital camera (I have an EOS350) has built-in safety against IR and, to get true IR, you'll have to remove this. This is not for us amateurs, and cannot be undone on Canon. You can get fake IR but the you'd have to compose your pic without filter, and then screw it on, you'd have to adapt focusing and take into account that lighting is critical. If you own photoshop, a quick way to get IR-like effects is to swap red and blue channels and then play with levels/curves.