http://canon-board.info/showthread.p...t=tamron+17-50
http://www.canon-board.info/showthread.php?t=58209
http://canon-board.info/showthread.php?t=13672
http://canon-board.info/showthread.php?t=12678
http://canon-board.info/showthread.php?t=51875
http://canon-board.info/showthread.php?t=31574
http://www.canon-board.info/showthread.php?t=52512
