Here are the Article that all of us need to know :
http://www.learn.usa.canon.com/resources/articles/2013/ef_extenders_pt1.shtml
http://www.learn.usa.canon.com/resources/articles/2013/quick_tips_videos.shtml?categoryId=12
http://www.learn.usa.canon.com/resources/articles/2013/memorizing_af_points.shtml
Enjoy, and Happy Holidays.
Surapon
http://www.learn.usa.canon.com/resources/articles/2013/ef_extenders_pt1.shtml
http://www.learn.usa.canon.com/resources/articles/2013/quick_tips_videos.shtml?categoryId=12
http://www.learn.usa.canon.com/resources/articles/2013/memorizing_af_points.shtml
Enjoy, and Happy Holidays.
Surapon