I had several people ask me how big and heavy the 800mm lens was, so I pressed my wife into service to snap a couple photos of me holding the lens attached to a camera body. This will give you an idea of the size of this lens. Since it is Canon's newest super telephoto lens, it has new lighter materials in it than their older 500 and 600mm lenses. So it is actually only 2 1/4 inches longer than the 500 and only slightly heavier. I have hand held a few shots with the 500 that came out good, but I did not even try with this lens. All shots were off a tripod and using a Wimberly Head.
Then I took a photo on the right of the 800 with it's lens hood attached standing
next to my 70-200mm zoom with it's lens hood attached. It really shows how big this lens is.