This lens will not be appealing for everyone, especially those of you who enjoy the convenience of a zoom lens and/or autofocus capabilities. This review contains my thoughts from the viewpoint of a photographer and will only briefly touch upon video. The features of the A7II and the upcoming A7rII are especially well suited for adapting lenses due to the in-body-image-stabilization. All mirrorless cameras allow for lenses to be adapted to them due to the short flange distance as a result of not needing a mirror. Focus peaking and magnification allow for the ability to quickly and accurately manually focus on your subject, which greatly improves user experience.
Sony’s native prime selection is continually growing with several interesting options from Sony as well as third party manufacturers. I desired a lens in the range of 35mm-55mm for which Sony makes the 35mm f/2.8 and 55 f/1.8 natively with autofocus for approximately $800 and $1,000 USD respectively. There are also the recently released manual focus Zeiss Loxia 35mm f/2 and 50mm f/2 in Sony FE mount for $1300 and $1,000. Samyang/Rokinon also make lenses in FE mount, but held little appeal for me due to their large size, weight, and 77mm filter thread. The retail price of the Voigtlander 40mm f/1.4 is $449 making it not only much cheaper than the Sony and Zeiss offerings but also with a faster maximum aperture. (Based on reviews, the Zeiss and Sony options are phenomenal).
As I stated earlier I was in the market for a slightly wide to standard lens with a fast aperture. Autofocus is of little importance to me as I normally shoot static subjects and am often on a tripod. The 40mm focal length is also familiar to me as I photographed with the EF 40mm f/2.8 STM and 17-40mm f/4L on a Canon 6d. The small physical size of the lens, even with the adapter, is one of the primary reasons I enjoy shooting with mirrorless cameras and chose M-mount lenses. Having the Voigtlander 75mm Heliar f1.8 and the VM-E close focus adapter also helped to make this lens an obvious choice for my needs. My prime lens strategy when consider how to augment my kit involves either attempting to double or halve my focal length depending on if I want to go wider or more telephoto. Using this strategy left 35mm and 40mm as good options, and when it came down to it the 40mm was less expensive.
Voigtlander lenses are made for Leica M-mount - Leica M-mount lenses are physically smaller than other lenses with full frame coverage (Leica and Zeiss M-mount options are highly regarded, but can come with astronomical price tags). The 40mm is well balanced on the A7II and looks great. While mirrorless cameras allow users to adapt a variety of lenses to them, with various pros and cons, M-mount lenses require the smallest adapter.
Filter size – I debated whether I should list the 43mm filter size as a pro or con, as it is somewhat obscure. Ultimately I decided it is a pro as the small size means less expensive filters and the ability to use step-down rings.
Multi system compatibility – I can use this lens on the Sony A7II as well as my Fuji X-E2 (with an additional inexpensive adapter). Since this lens has full frame coverage it can be adapted to virtually any interchangeable lens mirrorless system whether it be full frame, APS-C, or Micro 4/3rds
Solid metal construction - feels of a higher quality than Canon L lenses that I have used
Fast aperture – Even though the performance at the maximum aperture is less than stellar, it is still one to two full stops faster than the lenses mentioned above than cost significantly more. Photographing at f/1.4 is difficult even on autofocus lenses since the depth of field is so shallow. Stopping down will not only improve image quality, but it will also be more forgiving.
Bokeh – The out of focus rendering from this lens suits my taste quite well. There are smooth transitions and the bokeh stays circular in many situations (natural settings), even upon stopping down due to the 10-blade aperture diaphragm. Stopping down in other situations will cause 10 sided bokeh.
Chromatic aberrations seem to be fairly well controlled with lens, especially when compared to the 75mm, which exhibits strong purple and green fringing at large apertures. When trying to introduce CA by shooting at large apertures in high contrast situations I was only able to discern the slightest green fringing.
Wide Open performance
It is common for lenses to vignette wide open, but it is quite pronounced on this lens. Vignetting is correctable in post processing and improves greatly upon stopping down. Sharpness and contrast are also fairly poor wide open, and will again improve greatly when stopping down slightly. (Sharpness will be fine for many web applications, but I would not order a large print made with this lens shot wide open)
Files become clean and sharp when stopped down
Minimum focusing distance – Most modern rangefinder lenses, including this one have a minimum focusing distance of 0.7 meters which can be limiting for detail work. I enjoy getting close when shooting so to help combat the minimum focusing distance issue on M-mount lenses I purchased the Voigtlander VM-E close focus adapter. This helicoid adaptor allows photographers to reduce the minimum focus distance and therefore achieve greater magnification. A more cumbersome, but more cost effective option for reducing minimum focusing distance is the use of extension tubes, which I also implement into my workflow when necessary.
Minimum Focusing Distance: (Following images are shot at ISO 2500 are merely provided to demonstrate MFD)
Minimum focusing distance with VM-E Close Focusing Adapter by Voigtlander:
Minimum Focusing Distance with close focusing adapter and 16mm extension tube:
Lens hood – Lens hood is not included, but can be purchased separately
Loss of Exif data - The lens contains no electronic connections, therefore focal length and aperture will not be embedded into the file
Video – Exhibits focus breathing and focus shift. Aperture ring is also not optimized for video as it clicks in half stop increments.
Whether this lens works for you or not is dependent on your needs as a photographer. Ultimately the most significant reasons for purchasing this lens are the small physical size, large maximum aperture, and full frame coverage. Considering the current FE-mount line up, which contains some extremely well-received lenses, Voigtlander lenses offer a good value and make for interesting alternatives.