hi. can you please tell me if the lens physically moves at all when focusing? i'm trying to find a lens that doesn't extend or retract when focusing (like the canon 50mm 1.8 and 1.4 do) those two lenses won't work for me, the reason is because i want to use it with a steady cam and can't have it changing size AT ALL when focusing. i know people say don't use this long a lens for steadycam, but i want one lens i can blur background with on steadycam, and use the 70d amazing autofocus to track subjects. thanks for your reply!
