xtremediver 0 Posted September 16, 2006 Has anybody tried to change the focusing screen on a Canon 20d? I would like to add a different screen with the "rules of thirds" grid from the Katz eye optics company, and would like to hear from anybody who may have tried it already. Canon doesn't make a grid screen for the 20d that i'm aware of, so this looks like the best option. They also make it brighter for viewing like the older Beattie screens, and this would probably be a good option for underwater photography. Any one? Share this post Link to post Share on other sites