Testing the legendary Canon 85mm f/1.2L II - this (and it's sibling the 50mm f/1.2) are the fastest lenses Canon make - that is they have the largest maximum aperture and suck in loads of light!
Shooting wide open gives a very thin depth of field and blurred foreground / background. All that light gathering means lots of glass and contributes to the nickname of this lens as 'The Keg"!
A review is here.
Canon EOS 5D Mark II, f/1.2 @ 85 mm, 1/320, ISO 160, No Flash