And it never was a secret. It's been discussed in here a lot that if you plan to step up to either a 1D series body or FF sensor you should bypass the ef-s series lenses.And I, for one, wouldn't want to stick on an ef-s lens on a 5D and forced to use it as a 1.6X crop body.jack -- A few of my photos: http://web.mac.com/kurtzjack/or http://www.sportsshooter.com/members.html?id=4177