Thanks for the replies. Dave, the 17-40 focuses very close bare bones. I tried it with25mm tube and it was mms away from the subject it also has a 77mm thread so no good for a Raynox. Archibald, I no longer have the 100mm Macro Takumer, have been trying to edit my gear list but have not figured out how to do it yet. I am really looking forward to the Dragon and butterfly season when I believe the 100-400 will excel. I just want something for closer, smaller insects and only occasionally otherwise I would have kept the Takumer. I am actually trying to reduce the amount of gear I have so that I am left with a 7D body, 100-400 and 17-40 L lenses, macro tubes and a lens to use them on and a G1x.
David. Canon 7D Mkii. Canon 100-400L Mkii. Canon 100mm f2.8 USM Macro lens. Panasonic Lumix LX100