Quote Originally Posted by Bill M.
I really wouldn't sweat bringing in the 70-200 f4, especially if you have it ina backpack or toploading holster, security will most likely ask you to open up the backpack, see the camera, which really isn't big, and that will be the end of it.

You wouldn't believe the stuff you can fit into a diaper bag. Gotta go with a baby, though. Get enough dirty diapers in there and security wont dare open it. (The lens rental place might ask you about the smell on the 400mm f/2.8, though...)