I do not know that converting this lens to mount to FF camera (EF) can be that simple, u just use ur arms for the tool, confuse? read this article on flickr 5D+10-22mm: Sample photo's with 5D +10-22mm combo: 5D | EF-S 10-22mm f/3.5-4.5 USM | ISO 3200 | f/4 | @14mm You can see the vignetting clearly, but still acceptable image IMO *A little update Just want to remind you that ALWAYS USE FL(FOCAL LENGTH ) ABOVE 13mm!!! if not it'll hit the HOT MIRROR!&nbs...