[Brightcolours]

I don't get it. Shall I take those posts seriously, Frank and Rover? One wants 8mm more focal length, the other a bit faster aperture, no matter if it's usable. Those f/1.2 do come from the days when Film was really highspeed with around 6400 ISO. And grainy like a field of rocks. Or one of those early sensors which went beyond 1600 ISO.


With contemporary sensors,

• who needs f/1.2
  
• and is able to focus that properly
  
• and is willing to leave resolution, contrast and flare resistance completely on a mediocre side?
  

• I like f1.2, or even more f1.0 (but that is too expensive). Why? For DOF freedom. 
  
• A Canon 6D/5D mkIII/ 1D-X has no problem focussing a Canon EF 50mm f1.2 L USM.
  
• My Nikkor-S*C 55mm f1.2 is sharp enough at f1.2. It is also contrasty enough when not shooting against backlight. My Canon FL 55mm f1.2 gives very nice flares against back light/low sun, something many photographers will appreciate. A reason to keep it as specialty lens, for sure.
  

any idea why Nikon didn't, nor Zeiss with their latest "around 50mm" lenses? Certainly the price was no limit.

Yes, I have an idea why. Nikon F-mount diameter is too narrow to make a real f1.2 lens. All the 58/55/50mm f1.2 lenses Nikon has made have had trouble with this, with extreme cats eye highlights/bokeh discs as a result and because of that also a lot of loss of light. And swirling bokeh. There simply is not enough room mount-wise for f1.2 for a standard prime. 

The Canon EOS mount diamter is a lot larger (54mm vs. 44mm), providing room for bigger back elements. Both my 55mm f1.2's have way too small back elements. The difference to the Canon EF 50mm f1.2 L USM is big (and very noticable).

 

For Zeiss it is the same situation. If they were to design an f1.2 with large enough back elements, it would not fit Nikon F-mount. And Zeiss does not design EOS mount only lenses.

[Rover]

Sorry, Brightcolours, I don't understand this - can you clarify? I've heard that Sony E mount is similar (or even the same) mechanically as F mount, but there's a smattering of ultra-fast lenses usable on it (including the tailor-made Mitakon and SLRMagic 50mm f/0.95). Do they exhibit the kind of behaviour you've described? (I admit I have no first-hand knowledge on the matter, but people have been adapting old stuff to A7/A7r like crazy over at FredMiranda).

[Brightcolours]

Sorry, Brightcolours, I don't understand this - can you clarify? I've heard that Sony E mount is similar (or even the same) mechanically as F mount, but there's a smattering of ultra-fast lenses usable on it (including the tailor-made Mitakon and SLRMagic 50mm f/0.95). Do they exhibit the kind of behaviour you've described? (I admit I have no first-hand knowledge on the matter, but people have been adapting old stuff to A7/A7r like crazy over at FredMiranda).

You can't compare SLR lenses with lenses for mirrorless anyway... Lens design is different due to different distance to the film plane.

And then there is the difference between FF and APS-C needed image circle to consider also.

That Mitakon 50mm f0.95 shows to be too narrow too, with quite heavy cats eye-ing expect in the center of the frame.

http://www.sonyalpharumors.com/first-ima...0-95-lens/

[JJ_SO]

• I like f1.2, or even more f1.0 (but that is too expensive). Why? For DOF freedom. 
• A Canon 6D/5D mkIII/ 1D-X has no problem focussing a Canon EF 50mm f1.2 L USM.
• My Nikkor-S*C 55mm f1.2 is sharp enough at f1.2. It is also contrasty enough when not shooting against backlight. My Canon FL 55mm f1.2 gives very nice flares against back light/low sun, something many photographers will appreciate. A reason to keep it as specialty lens, for sure.

Yes, I have an idea why. Nikon F-mount diameter is too narrow to make a real f1.2 lens. All the 58/55/50mm f1.2 lenses Nikon has made have had trouble with this, with extreme cats eye highlights/bokeh discs as a result and because of that also a lot of loss of light. And swirling bokeh. There simply is not enough room mount-wise for f1.2 for a standard prime. 

The Canon EOS mount diamter is a lot larger (54mm vs. 44mm), providing room for bigger back elements. Both my 55mm f1.2's have way too small back elements. The difference to the Canon EF 50mm f1.2 L USM is big (and very noticable).

 

For Zeiss it is the same situation. If they were to design an f1.2 with large enough back elements, it would not fit Nikon F-mount. And Zeiss does not design EOS mount only lenses.

Excellent points, Brightcolours!


Is that also the reason why Canon has 85/1.2 and Nikon don't? I recall Zeiss making such a lens for Contax years ago in a limited edition (wooden case and everything, so probably not much of those lenses have seen some film surfaces behind them).


Still, not my cup of tea, those large apertures. For me f/1.4 is alright, I learnt how to handle those and guess f/1.2 is much harder for getting the focus right. At least with Nikon AF, I think Canon makes better ones.

[Brightcolours]

Excellent points, Brightcolours!


Is that also the reason why Canon has 85/1.2 and Nikon don't?

Probably, because 85mm f1.2 is prestige, and I can't imagine Nikon not doing it if they easily could.

The 1st Canon 85mm f1.2 was on FD. I don't know too much about this lens, but its back element fills the mount. My guess is that it is a bit narrow there too, the lens does seem to "swirl" quite heavily anyway.

 

The EF versions have a much larger back element, so big that they cut away a part to make room for the lens contacts (similar to the 50mm f1.0 L USM).



 

I recall Zeiss making such a lens for Contax years ago in a limited edition (wooden case and everything, so probably not much of those lenses have seen some film surfaces behind them).


Still, not my cup of tea, those large apertures. For me f/1.4 is alright, I learnt how to handle those and guess f/1.2 is much harder for getting the focus right. At least with Nikon AF, I think Canon makes better ones.

On most bodies the focussing accuracy with the 85mm f1.2 L USM (II) is fine, but the lens is much slower to focus than your Nikkor 85mm f1.4. And 85mm f1.4 of course is pretty big, aperture wise!

[JJ_SO]

On most bodies the focussing accuracy with the 85mm f1.2 L USM (II) is fine, but the lens is much slower to focus than your Nikkor 85mm f1.4. And 85mm f1.4 of course is pretty big, aperture wise!

I used it yesterday evening in dim light and with dancing people and was happy to get some shots where the focus was alright, but with moving subjects it's more saying about my technique and lack of understanding the AF ( not to get every picture sharp ) than about the lens. Although it was in service last year because the AF motor didn't work properly. So my relation to the lens is not a very confidential one, I don't see myself relying on it in every moment. But that' sailing on a high level, I prefer to be happy about the good shots and get more experience.


Anyway, if Sigma comes out with a 85/1.4 Art type I'll give that a try. And then there's still an option to switch to Canon one day.


Edit: Just forgot: thank you for posting the picture, now I understand better. Interesting solution with the electrical contacts in front of glass.

[Rover]

You can't compare SLR lenses with lenses for mirrorless anyway... Lens design is different due to different distance to the film plane.

And then there is the difference between FF and APS-C needed image circle to consider also.

That Mitakon 50mm f0.95 shows to be too narrow too, with quite heavy cats eye-ing expect in the center of the frame.

http://www.sonyalpharumors.com/first-ima...0-95-lens/

Ah, so in this case it's the flange distance that makes or breaks the design. Makes sense. Thanks.

[wojtt]

The MTF data for the Sigma 50 Art is out : http://sigma-global.com/en/lenses/cas/pr.../data.html

It seems like a very decent performance when comparing to the Nikkor 50 1.4, and probably also compared to other 50mm lenses barring the Otus..

 

I hope though, that the pricing will be more like the Sigma Art 35mm 

[popo]

http://www.canonrumors.com/2014/02/sigma...irst-time/

 

Claimed crops from the Sigma lens above. Take it for what you will.