I need to photograph a collection of old documents that cannot be run through a copy machine. The documents are standard letter size and will be on a flat table. I have a Canon EOS30D. I need to get a lens that does not distort the image. Further I am not sure what the lighting conditions will be at the location. I really do not want to buy a EF-S lens as I am hoping to upgrade to a full frame Canon soon. I have been told to get the 50mm macro lens. I was also looking at the 24-70mm F2.8L wide angle zoom. Any thoughts?