I just posted the review on the 58mm f/1.2 Noct.
Here is the review of the 50mm f/1.2 Ai-S.
The reviewer is very enthusiastic about this lens also
Here are the Imatest scores of the 3 lenses (50mm f/1.2 Ai-S, 58mm f/1.2 Noct, and the 58mm f/1.4 G).
QUOTE:END QUOTEThe results are clear: the Noct is peerless in center sharpness at the widest aperture.
(Its very low mid- and corner-sharpness are doubtless what create its unique look.)
The 50mm Ai-S is the weakest wide-open, but by f/2 it equals the 58mm G, and
by f/4 the 50mm Ai-S is the sharpest of the bunch across the frame.
The 58mm is an also-ran, excelling at nothing, until f/8, where it is merely comparable to the others.
(Though it is "pretty good" wide-open, it does not equal the Noct, though its performance does appear more balanced.)
- The 50mm f/1.2 Ai-S is $700.
- The 58mm f/1.2 Noct is $3,200+
- The 58mm f/1.4 1.4G is $1600
Of the bunch, the 50mm f/1.2 Ai-S is clearly the best value, by far, beating both across the board from f/4 to f/11.
And the 58mm f/1.4G AF seems to be over-priced. It is midway between the 50 Ai-S and the Noct from f/1.4 to f/4, yet excels at nothing at any point, until f/8, where they are all fairly comparable.
In the end, the Noct does own the "wide-open" territory ... it is clearly very unique there.
The Noct's greatest performance lead over everything appears to be at f/2, in center sharpness only.
It is perhaps the great disparity in the Noct's center-to-corner sharpness wide-open that creates its character ... up to f/4 ... to the extent that those people who shoot in this range are willing to "pay to play" there
Jack