Aah noo... THIS is a lens
http://www.luminous-landscape.com/re...es/600mm.shtml
(the body behind it is a 6x7, not a puny DSLR)
Then there is massive beast from Zeiss - 212 mm clear aperture and a hefty 16.5 kg... http://www.smt.zeiss.com/C12567A8003B8B6F/EmbedTitelIntern/Mirotar5.6_1000mm_e/$File/Mirotar5.6_1000mm_e.pdf
I still think one of the funniest things I did a while back was setting up a C8 at The Gap at Watsons Bay for the start of the Sydney Hobart, many years ago. Dozens of canonites, nikonites and pentaxians were giving me the evil eye 'cause I had a lens that was waaaayyyy bigger than theirs! Size does matter, to some.
Other oddball large lumps of glass:
Sigma 500 f/2.8
http://www.dpreview.com/news/0801/08...igma250500.asp
Zeiss made a 250mm f/1 and a 400mm f/1.5 (!) way back during WWII (it's a quarter the way down this interesting page)
http://www.dg77.net/photo/tech/fast.htm#proto