Hello cmar! I just read the review you wrote about four years ago regarding the Tamron 70-300mm F4-5.6 AF Di LD Macro lens, model code A17. I just bought this lens recently as being made for digital SLRs, frankly assuming is was made for APS-C sensors (both my DSLRs use this sensor). I see by your review comments that this lens is a full frame lens, and you commented on the crop factor. I really can't find anything in the owner's manual to dispute that, or confirm it for that matter. How did you find out that information, if I may ask? Thanks much. --Mark