AF-S Nikkor 50mm f/1.4G vs Nikkor 50mm f/1.2 ai-s

[acgiannopo]

I did a little comparison test between the AF-S Nikkor 50mm f/1.4G and the legendary Nikkor 50mm f/1.2 ai-s.
At first, I wanted to compare sharpness and chromatic aberration wide open but I tested other aperture values too, sharpness towards the corners, coma and quality of bokeh, etc.
What surprised me was that despite the difficulty of nailing the focus in the older Nikkor, the lens looked to my eyes sharper than the newer one wide open and continued to be sharper in every other aperture. It lacked though in coma, chromatic aberration and sharpness towards the corner with the newer one being better. Another thing that really amazed me was the fact that even though I dialed -2 stops in exposure compensation, the newer Nikkor continued to overexposure the scene.
The images below are screenshots from side by side comparison on LR on 100% magnification. The shots are handheld, iso 800, tried to do my best in replicating the shot.
Focused dead center, on “DELL” logo on my laptop.

[beryllium10]

Interesting, and your conclusions may be correct (I don't own either lens), but I'd be wary of assessing sharpness at f/1.2 and f/1.4 from hand-held images.  The smallest movement of the camera between focusing and exposure will detract from sharpness, and any pitch or yaw will impact the corners.  Note - I think you already discovered the sensitivity of focus testing with your post on the 85mm/1.4 (http://nikongear.net/revival/index.php/topic,8381.0.html).  Better to use a tripod.  Cheers,  John

[pluton]

The subtle differences between lenses can be interesting...especially when they are your own lenses.
I have found that most of the budget-priced non-exotic 50mm lenses to be of limited usefulness wide open.  I have tried to seek out situations where their wide-open image quality might work for a shot.  Often, the visible manifestations of the aberrations are ugly and distracting.
As Dirty Harry might have said: "A man's got to know his [lens']limitations".
IMO, If you spend more $$$ and choose wisely, you can get something more useful wide open. 
I do remember that the 50/1.2 AiS I had in the film days was the best 50mm---at any stop---I had used up to that point.

[acgiannopo]

Interesting, and your conclusions may be correct (I don't own either lens), but I'd be wary of assessing sharpness at f/1.2 and f/1.4 from hand-held images.  The smallest movement of the camera between focusing and exposure will detract from sharpness, and any pitch or yaw will impact the corners.  Note - I think you already discovered the sensitivity of focus testing with your post on the 85mm/1.4 (http://nikongear.net/revival/index.php/topic,8381.0.html).  Better to use a tripod.  Cheers,  John

I think i might do a comparison between these two and the other 50mm i own, an f/1.8 e series ai-s using a tripod in order to be more "scientific". I know that this test was more of a "daily use" but i found that focusing the 50mm f/1.2 was easier than the 85mm. The logo was bigger than the f/1.2 mark used in the other test and the focusing distance shorter so the image in the viewfinder clearer for manual focusing.

[acgiannopo]

The subtle differences between lenses can be interesting...especially when they are your own lenses.
I have found that most of the budget-priced non-exotic 50mm lenses to be of limited usefulness wide open.  I have tried to seek out situations where their wide-open image quality might work for a shot.  Often, the visible manifestations of the aberrations are ugly and distracting.
As Dirty Harry might have said: "A man's got to know his [lens']limitations".
IMO, If you spend more $$$ and choose wisely, you can get something more useful wide open. 
I do remember that the 50/1.2 AiS I had in the film days was the best 50mm---at any stop---I had used up to that point.

I remember the days i first used the AF-S. It was a mess wide open. It took me some time before noticing that needed AF correction through my camera in order to get decent images wide open.