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

Close Range (1.2m) Performance at f4

Extreme corner crops (full frame re-res'd to 6000 pixels)

Again, because this pair are so closely matched, the 400D capture has been resampled to 6,000 pixels wide (from 3,888 px) and matching crops taken. Again, allowance must be made for a slight advantage handed to the Pentax whose longer focal length allocates a few more microlenses the privilege of rendering her Maj's noggin.

Canon 85mm f1.2 L MkII at f4 (corner)	Pentax SMC A* f1.4 at f4 (corner)

I must confess this has me all wobbly: I was not expecting the Pentax to outperform the Canon here. The 85L has a reputation for being peerless at this aperture: yet the SMC is clearly sharper, better delineated and clearly comparable in colour rendition. Truly stellar 'corner' performance – well worth the full frame mod?

Centre frame crops (from full frame re-res'd to 6000 pixels)

Canon 85mm f1.2 L MkII at f4 (centre)	Pentax SMC A* f1.4 at f4 (centre)

Even at nearly 200% enlargement, this is a tough one to call. The Canon 85L II appears a little more contrasty centre frame, as it did at f1.4. There is (quite literally) the merest hair more resolution in the Pentax image, but this apparent advantage is mitigated by the larger image size. On balance, I think perhaps the Canon does just enough to be preferable, but we are seriously nitpicking here . . . .