Perhaps it is Macro and M compatible. Like some integrated macro tube that can be used for macro on normal DSLR and to get the back focus right on EOS M. They would just have to find a way to make this mountable on both EF-S and EF-M mount.
But I think it is something else really special. Because neither the focal length nor the aperture are special at all. I would have expected the lens to be wider than 17mm to provide something not covered by the 17-55 f/2.8 IS USM.
« Last Edit: March 14, 2017, 01:53:40 PM by midluk »
5D4, 70D+BG E14, EF 24-70 f/4L IS, EF 16-35 f/4L IS, EF-S 17-55, EF-S 10-22, EF 100 f/2.8L IS macro, EF 70-200 f/4L IS, EF 100-400 L IS II, 2x 600EX-RT, 430EX III-RT