Looking it up it seems like it ought to mount and autofocus on a Canon body, had it been Nikon it would of been a whole other can of worms. It's an older design though (Sigma did 2 170-500mm lenses, one APO Aspherical and one APO DG...more or less same design but the DG had updated coatings on the elements) and won't have any form of optical stabilization. Will make it a handful to shoot handheld, bit lighter than my lens but at 1.3kg it's still a big lump of glass & plastic/metal to haul around and shoot. But from a tripod that's a moot point. Bit of a disclaimer, never used anything but a Sony camera so got no hands on familiarity with the D3300 and that Sigma. Time to break my gear out for a little walk here, hopefully find my favorite little subject again...Azure Kingfishers. Got this shot around a month ago and keep on going back to the same reserve with the hope that it will allow me to get this close again.