Time for another update.
After careful scrutination I have learned the following:
- The Noct is sharper in the center at f1.2. Moving towards the far corner the image suffers from some loss of sharpness and increased softness/vignetting.
- The NeoNoct is clearly not as sharp (but still very portrait good) in the center at f1.4. Sharpness is kept better afloat towards the corners and at the far corners sharpness/softness/vignetting is much better than the Noct's.
- Coma; both lenses are behaving quite well, with slight increase in gullwinginess from close to infinity. By f2.8 all traces of coma are gone. Interestingly, the 50/1.2 Ai-S, although terrible wrt. coma at f1.2-2, exhibits the same coma correction at f2.8.
- Bokeh; again very similar behaviour, with the Noct producing at close focus softer proximal one and distally the NeoNoct has a slight advantage. The 50/1.2Ai-S is not bad but absolutely not in the same league.
- Point light source bleeds; when shooting wide open the NeoNoct show less bleeding than the Noct.
- Sunstars when stopped down; this is Noct's department so no need for NeoNoct to play ball here.
- Flare; this one goes to the new Emperor. The predecessor lacking the nano curtain does struggle (like most older lenses).
- Focus shift; both lenses perform distal focus shift when stopped down. In order to achieve optimal focus, LV/stopped down focusing is a must. For portrait shooting with the NeoNoct a best fit AF fine tuning is a solution.
- Lateral CA; the NeoNoct shows less. CA from either lens is easily dealt with during PP.
- Axial CA; both lenses show magenta fore and green aft color artifacts. This is common with "under-corrected" lenses. Removing this is generally an easy job with ACR or NX-D (I still have to learn other raw converters).
- Relative focal length; the Noct is slightly wider than the NeoNoct.
- Manual focusing with and S-type focusing screen; both lenses are absolutely fine but the manual Nikkor has a clear advantage mechanically. (It takes a lot of practice to be able to nail focus with these speedy Gonzales's).
I will follow up with images supporting my findings.