Well, people mount their 1D series (which is 3.5lbs+) to the end of tripod mounted super-telephotos all the time, so there's no doubt in my mind that the EOS mount can take at least that much.

Your Rebel doesn't weigh enough to warrant concern about breaking the mount, and neither of the 70-200s will outweigh Canon's.


You're fine!

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See my user profile for gear information. Then forget about that stuff and go take pictures! And then some more pictures!