Thanks Traveller. That lens is amazing. I got it refurbished from the Canon store for $599! But even at full price ($999) it's a bargain. It's also remarkably light, because of the refractive optics, and has a very good image stabilization system. It's a lens that could only work on mirrorless cameras, because of the fixed F11 aperture. Mirrorless cameras don't have the same AF limitations as DSLRs.
Alastair
Your 800 (?)mm lens seems to be amazing....this is very clean...and I like rabbits, so what the hell....I love this, though the bird is good also. Traveller