Voigtländer 40mm f/1.2 Nokton: E-mount versus VM-mount
The new Voigtländer Nokton f/1.2 which was announced last Autumn comes in two distinct versions, one for VM-mount (Leica M) and one for Sony E-mount. These are ultra-fast general purpose lenses that could satisfy most users. With the unusual 40mm focal length they sit neatly between the more traditional 35 and 50mm standbys, offering the best of both worlds. Both are optically identical, according to Voigtländer, but there are some significant differences in design and build.
Flaghead, the UK importers, sent us the E-mount version for use with our review copy of the Sony A7III. After having played with the VM lens and knowing that the performance is going to be the same, I was surprised by some of the material variances.
In design, the E-mount Nokton is very similar to the VM. At a casual glance at the photographs, they do look very much alike. But in the metal, this is not the case.
Below: Sharpness not in doubt and the image quality from the Sony is impressive — full frame on the left, crop on the right. Nokton E on Sony A7III (click images to enlarge)
Size and weight
The Nokton E is bigger. It is 58.1mm long (at infinity) compared with the 43.3mm of the ZM, and 70.1mm maximum diameter whereas the ZM lens nearly 10mm slimmer. Like the VM version, this lens focuses externally so is longer at its closest focus distance of 35cm (the Nokton VM focuses down to 50cm on a mirrorless camera, 70cm on a rangefinder). When extended, the lens is 64.6mm compared with the 47.2mm of the VM.
The difference in length is probably accounted for by the need to keep the lens/sensor distance optimal. The VM lens has the added width of the mount to help maintain the difference, so the E version has to be longer to compensate. The E-mount lens has a broader focus ring to fill the extra space on the barrel, thus providing a useful handling advantage. As a result of the greater thickness, the filter thread is 58mm in diameter compared with the 52mm of the VM lens.
Weight is also a significant factor. While the VM Nokton is a lightweight 315g — remarkable for such a fast prime, and consistent with similar M lenses — the fatter E Nokton tips the scales at 420g.
Both lenses appear to be built to the same high standards and are exceptionally presented for the price.
Driving on the right
A further significant difference is that the aperture ring abandons the Leica standard — where the fastest aperture is on the left — and adopts Sony’s preferred layout of the wider apertures to the right. For experienced Leica users, it’s a bit like driving on the “wrong” side of the road (from a British perspective, as always). Odd, but you soon get used to it. It would, however, be perverse to choose the contrary layout in contrast to other E-mount lenses.
The aperture ring on the E-mount lens can be de-clicked so that it is a smooth progression. This is intended mainly for videography use but I find it quite interesting to use it also for still photography. There is an adjustable ring next to the aperture ring and this is engaged by pushing the aperture ring forward. The outer ring can then be turned by 180deg so that the bottom yellow market comes to the top of the lens to indicate clickless mode.
What I do find odd is that the front element of the E-mount Nokton appears to be smaller and is considerably recessed, quite strange for such a fast lens. The VM has a more prominent front element which helps give it the mini Noctilux appearance which I’ve mentioned before. In some ways, then, the E lens looks less impressive from the front. It's less of "I'm a very fast lens" compared with the Nokton VM. After pondering this difference, my conclusion is that it is an illusion created by the fatter E-mount lens. The front element fills out the VM lens while it is diminished in the Nokton E.
Another difference is the fitting for the hood. The VM lens has a chrome bayonet ring so that the accessory hood is attached without interfering with the filter thread. On the E lens, which does come with a hood which screws into the filter thread in a similar manner to those cheaper third-party accessories that are available for most lenses. If you wish to fit a protective filter to the Nokton E it must ride piggyback between the lens and hood. That's not my favourite design. In mitigation, though, the hood is all metal and substantial, fits perfectly and helps protect that recessed front element. I do not think a protective filter is necessary.
In operation, however, the E-mount lens has a major trick up its barrel. It is intelligent and has an electronic connection to the camera. Not only does this identify the lens to the camera, thus populating EXIF data, but it also permits some operational enhancements. The camera can detect movement in the focus ring and automatically bring up the magnification focus aid. In this respect, it works just like a native auto lens when set to manual. There is no need to press a magnify button before every shot as there is with every other mirrorless camera on the market. Only the Leica M performs this trick thanks to the detection of movement in the rangefinder mechanism.
The electronic connections also transmit aperture settings to the camera. The manually selected aperture is visible in the viewfinder or on the screen. Of course, the aperture ring is fully manual so it cannot be changed from the camera as is possible (or necessary) with E-mount autofocus lenses. However, the display of the chosen aperture in the viewfinder is a useful feature and serves as a reminder of the setting.
In most respects, therefore, the manual Nokton E works just like a native Sony lens set to manual operation. This version is quite unlike the VM lens which is as dumb as any Leica M optic: Don’t bother checking EXIF data when using the VM version; you have to remember what lens and what settings just as you do with a film camera. As I know to my cost when using different cameras and lenses, trying to remember settings several weeks down the line is a daunting task. The Nokton E makes life easier
So why is the Nokton E preferable to a native Sony autofocus prime? Because in essence it is a traditional manual lens with a focus ring that stops at either end — albeit a rather long 150deg throw in common with the VM version — and has the handling advantages of a manual lens. However, it’s a manual lens at heart with electronic benefits.
My initial conclusion, then, is that the E-mount version is by far the better option for Sony users, as it should be. Only if you intend also to use the lens on an M or other mirrorless cameras is the VM mount the best choice. Yet there is a penalty to be paid for the increased sophistication of the Nokton-E. Until I held it, I had imagined that both versions would be very similar in size and weight, but it turns out that the differences are quite dramatic. And all for good reasons.
Both of these lenses are superb performers and, as far as I can tell, produce identical results. The E lens has been extremely well received by reviewers and is considered a premium prime for Sony cameras. The VM version has had less attention so far, but it is a hidden gem — a new design, well made and available at a bargain price compared with Leica or, even, Zeiss lenses. If you wish to use the Nokton on different cameras, including the Leica M, and Sony, then the smaller, lighter but equally proficient VM version is the better choice.
A review of this lens, together with a brief overview of the Nokton E is in preparation.