Which macro lens for 40D

[MJA]

Would you get the 100mmf/2.8 or the 180mm f/3.5L?

[Wilt]

the shorter FL

[jj_photography]

100 f2.8 would be a good start to go with. Have a look at Fred Miranda website (http://frdmiranda.com) or The Digital Picure (http://www.the-digital-picture.com/Reviews/Canon-EF-100mm-f-2.8-USM-Macro-Lens-Review.aspx)