Canon 85mm f1.2 L (Mark II) vs.
Pentax SMC-A* 85mm f1.4

Close Range Performance at f1.4

Extreme corner crops from Canon 400D frame (150% magnification)

To see what's really going on in the corners, these 100% crops have been further enlarged to 150% using Bicubic Sharper, after some modest USM was applied. You'll note in all cases that the Pentax 85mm is a longer focal length than the Canon. Which, if either, are truly 85mm is anyone's guess.

Canon 85mm f1.2 L MkII at f1.4 (corner)	Pentax SMC A* f1.4 wide open (corner)

That is an immensely impressive capture by the Pentax SMC A – wide open, against the Canon half a stop down. You'll have to excuse me while I go a bit purple here, becuase that is the sharpest 'corner' I ever seen any lens produce at this aperture (f1.4). Just stunning. For the centre frame assessment, we'll revert to 100% views:

Centre frame crops (150% magnification)

Canon 85mm f1.2 L MkII at f1.4 (centre)	Pentax SMC A* f1.4 wide open (centrer)

However, like a true champ, the 85L Mk II refuses to be counted out, counterpunching with a centre frame performance that puts it back in the fight. Better contrast, higher resolution and generally more yumminess. The Pentax is still ahead on points, though . . .