Thanks for the input so far everyone. I still have the 10-22mm so it would be possible to convert it to use with a FF body, but from what i read i could damage my FF camera (and possibly 1.3) if im not careful. When shooting at wider than 12mm the rear element can touch the mirror and i'm not willing to take this risk, because this is just the thing that would happen to me So, i think i'll add it to the marketplace instead. Please continue the 17-40mm vs 15-35mm discussion, because i havent made up my mind about those two yet. Thank again!
I use my 10-22mm on my 6D and it's awesome, very sharp in the corners stopped down to ƒ8, softer wide open but that's ok for what I shoot most of the time. Would love to get a 16-35mm but I think I will just eventually settle not he Samyang 14mm ƒ2.8
You can see some 10-22mm shots on FF here: http://www.flickr.com …k/sets/72157634466773339/
Since the 10-22mm and 17-40L are about the same price, I never understood why anyone would want to modify the 10-22 for use on FF. Just sell it and use the funds to buy a 17-40L -- that is what I did. Having some focal length overlap with a 24-xx zoom can be quite convenient, as it can reduce the number of lens changes.
I modified mine as I still have my crop camera (600D) so it's handy using it on both cameras. IMHO the 10-22mm is slightly better than the 17-40mm in sharpness.