help picking out the right lense

[vietcu]

Hey guys, I have a Canon 10D using a 100mm Macro lense. I have been using this to take mostly top down shots of frags and close up of corals, and rely on it heavily. What I need to do now is take whole colony pictures of my corals. I would say anything from the 3"-10" range of coral size. I am usually about 10" to a little over 1' away from the coral from the end of the lense. I am trying to figure out which lense that will allow me to take a whole shot of my corals without being too close nor too far from it. Thanks

 

[blurry]

bump - I'm also interested :)