[Voigtlander Super Wide Heliar 15mm f4.5 v Sigma 12-24mm f4.5-5.6
[published january 2006]
The Canon 5D/Voigtlander Rangefinder
The Voigtlander 15mm f4.5. Where on earth are you going to put THAT?
First: yes, you can use Voigtlander’s true wide angle lenses on Canon digital cameras: here’s my 15mm f4.5 SL on an EOS 5D. They also make a very nifty 12mm rectilinear (more on this later). For mounting details, please below.
Behind the lens (roughly 15mm behind the rear element) is a state-of-the-art picture-taking computer temporarily retarded to the complexity of a box brownie. You can’t use the optical finder because there’s a lens where the mirror should be. You can’t use the metering because there’s a lens where the mirror should be. And you can’t autofocus because this is the 1920s. But you can take pictures.
Other than sheer bloody-minded perversity, why would you want to do this? Because these little rangefinder optics are not inside-out telephoto lenses. When Voigtlander say the 15mm SL is rectilinear, they really, really mean it, to a degree that retrofocus SLR optics can’t approach. Rangefinder wide angles are much simpler to design, and have exit elements much closer to the film or sensor plane, making corner sharpness and field flatness much easier to achieve. Oh, and they are cheap!
It is generally agreed that the finest wide angle lenses are the Mamiya 7 43mm and the Zeiss Biogons. Anyone who has used either, especially those currently struggling to shoot architecture with a Canon 1Ds II, tend to come over all wistful and nostalgic at the very mention of their name. But can the Voigtlander Super Wides bring some of their ancient rangefinder voodoo to the age of digital capture? Can they slay the three-headed dragon of distortion, inadequate resolution and chromatic aberration? Or will the quest for wide angle image quality prove too perilous for even these exotic creatures? Let the trials commence….
Fortunately, Voigtlander’s range of highly regarded lenses are available in Nikon AIS mounts designed for older cameras that can operate with mirrors permanently locked up. A commonly-available Nikon to EOS adaptor takes care of mount compatibility without problems. There are some superb optics in this range that can be experimented with for very little outlay. The APO Lanthar 120mm Macro, for instance, is considered to be among the very best of its type available, competing on equal terms with the Leica 100 APO and Zeiss 100mm variants, according to some.
Lacking the Nikon bodies’ mechanical MLU, however, Canon users are forced to deploy more basic measures: these tests were accomplished by carefully raising the bottom edge of the 5D mirror to a horizontal position, while gently inserting the barrel of the lens underneath. The diameter of the rear element cowl is such that the weakly-sprung mirror comes to rest stresslessly on the lens itself.
Somewhat to my surprise, the camera didn’t error when the Mirror Lockup Custom Function was enabled. Beyond a slightly disturbing increase in the volume of the mirror slap (it was, after all, hitting the lens!), no ill effects were observed, and the camera reverted to normal operation without difficulty. No doubt this entirely invalidates your warranty blah blah blah and I couldn’t possible endorse or take responsibility for blah blah blah, etc, etc, etc.
Thanks to Kit Laughlin for suggested the simple and effective measure of attaching to the top half of the long rear cowl a strip of 2mm self-adhesive foam. This not only damps the impact of the mirror on the lens housing, but it reduces its travel, and therefore the velocity at which it arrives.
Tests conducted with Canon 5D at ISO50 shot RAW with mirror lock up and processed via Capture One 3.7.3 into 8-bit Adobe RGB, sharpened in PhotoShop (150/0.5/4) and converted for web with BoxTop ProJPEG. All captures manually focus bracketed.