I just got my new Voigtlander/Cosina 35 mm Nokton f 1.2 version III from cameraquest.com, 24 hrs after ordering it ($ 1,050). I already had the version II. This new one is a real improvement: shorter (which means better clearance in the viewfinder), lighter, new lens design (9 elements in 7 groups instead of 10 elements in 7 groups int version II). Now how does it perform? To make a long answer short, better. The new optical design allows for better sharpness at wide apertures (f 1.2 and f 1.4) from edge to edge (edges were soft to say the least at those apertures with version 2). The only caveat I can see is that it looks as if there is a little more vignetting but nothing not solvable if you work digitally (most image-processing software will take care of that and for those who systematically add vignetting to their images in Lightroom—I happen to know a lot of these and they drive me crazy—you do not have to do anything).
The reasons I bought it were that it seemed to address the two caveats mentioned above: weight and length. And it does: 50.5 mm long against 62 mm, 332 g against 470 g. The lens has also been redesigned to allow such a compression in size: 9 elements in 7 groups instead of 10 elements in 7 groups for the previous version (II) [for a comparison, the Rolls Royce of 35 mm, the Leica Summilux has 9 elements in 5 groups]. The aperture is composed of 12 blades which provides a smooth out-of-focus image (aka bokeh). The lens is very sturdy with an all-metal barrel. Both version II and version III contain aspherical elements which account for the image quality one gets out of these two lenses. At this point version III is between $ 100-150 more expensive than its predecessor (around $900 versus $1050) and in my opinion is worth the difference although in image quality both lenses are very close.
After testing version III with my M240 on Monday, I went out again with the older version II on Wednesday and here are my conclusions:
1-At its widest apertures (f 1.2 and f 1.4) version III looks definitely sharper (comparison made at 100% enlargement in Adobe Camera Raw) especially on the edges and in the corners. Those corners were soft with version II. As a note, they can be extremely soft in the two other iterations of 35 mm lenses produced by Voigtlander, the f 1.4 Classic and MC (Multi-Coated) which are very compact but whose images are really soft in the corners at f 1.4 and f 2.
2-I looked at images minimally processed (raw) and uncorrected (jpg) by either by the camera (unlike other digital cameras, Leica Ms only recognizes and corrects the last generation of their lenses which integrate a 6-bit code) or the software (no profile to be found for the Nokton III). Under such circumstances vignetting looks slightly more pronounced in version III than version II. This latter issue being easily correctible does not stand as an issue for me.
In conclusion, when it comes to quality and budget, I would highly recommend the Voigtlander 35 mm Nokton f 1.2 version III. I am going to make further comparison with the Fuji X-series 23 mm f 1.4 (more voluminous although it is for an APS-C format sensor, and the new Nikon 35 mm f 1.8 (even more voluminous) [yes, after all, and with age, size matters to me].
