Pekka Buttler, 08/2023
The table below summarizes the lens’ key specifications (Measurements based on pictured sample):
|Subfamily (if applicable)
|Filter ring diameter
|Lens element count
|Lens group count
|Aperture blades (S/R/C)5
|Minimum focusing distance
|Has manual aperture ring
|Has Manual focus ring
• This lens is a DKL-mount lens (see the article on the DKL mount), and therefore does not have an aperture ring (the aperture ring was on the camera-end of the mount).
• All DKL mount lenses – irrespective of manufacturer – follow a very similar design and aesthetic. Part of that design is defined by the structure of the leaf shutter integrated in the mount, but it seems that manufacturers followed a common playbook regarding colors (silver), typography, ergonomics and usability.
• While some of these aspects are admirable (such as the red ‘whiskers’ that change to indicate depth-of-field at the chosen aperture), others are a bit tedious (generally narrow, rather heavy focus rings).
• The Septon has seven lens elements (as alluded to in the name). In its day it was the top-of-the-line lens and the faster of the two 50 mm lenses that Voigtländer offered for its flagship SLR line. Together with the very rare 40 mm f/2 Skopagon, the Septon is one of the fastest lenses available for that line.
• The Septon was designed by Albrecht Tronnier, who has a few famous designs of fast standard lenses under his belt (including the famous Zeiss Ultron).
• The starting point of the Septon has most likely been the Voigtländer Ultron 50 mm f/2 (Designed for Voigtländer’s Promiment rangefinder cameras), which could however not be used as such (due to the leaf shutter’s demands on back focal distance and lens rear-end diameter). In order to fit the constraints of the DKL mount, the lens was redesigned, including the meniscus-formed second element.6
History of Voigtländer
The company Voigtländer was founded in 1756 in Vienna (Austria) by Johann Christoph Voigtländer, and the company initially focused on manufacturing scientific instruments. Soon after the beginning of the 19th century, an increasing share of the company’s business was concerned with optics ranging from lenses to binoculars. In 1840, Josef Petzval designed a lens for Voigtländer which to this day is known as the Petzval lens. Soon thereafter Voigtländer opened a branch office in Braunschweig (Germany) and by 1862 the company moved its headquarters there.
The late 19th and early 20th century were boom-times for the entire photographic industry, and Voigtländer – while having its ups and downs – was generally doing well. Even so, it seemed that the mother lode eluded Voigtländer. Instead companies such as Leitz/Leica, Zeiss/Zeiss Ikon and Rollei (a company founded by two ex Voigtländer employees) were stealing the limelight or raking in the profits. While Voigtländer cameras were not without success (or innovation), it seems evident that the company’s competitiveness rested on its lens design and manufacture – a field wherein the company had a track-record that most of its contemporaries envied.As a result, Voigtländer ended up first (1925) in the hands of a chemistry giant, only to be sold to arch rival Carl Zeiss in 1956.
Bessamatic/Ultramatic: A camera system built around a mount
Every combination of an interchangeable lens camera and a lineup of lenses is to some extent defined by the lens mount. For instance, the flange focal distance chosen will have ramifications both for camera design and lens design.
However in the case of the Bessamatic and Ultramatic line of cameras, this is more so, because …
The long story is in the JAPB article on the DKL mount, but I’ll do a short recap here:
In still cameras, there are really only two ways to construct a shutter: One alternative is to use a leaf shutter that uses a set of metal blades to totally block the light path. Another alternative is to use a focal plane shutter (a curtain of cloth or metal) to block the light path. Both have their pros and cons and this is not the time nor place … suffice it to say that leaf shutters are a natural choice for viewfinder and rangefinder cameras, whereas most SLRs rely on a focal plane shutter
Importantly, until the 1950s leaf shutters had been the dominant way of constructing a shutter, and there were two West-German companies that basically owned the high-end leaf shutter business: the Deckel company manufactured Compur leaf shutters and their rival Gauthier manufactured leaf shutters called Prontor. Seeing two megatrends (interchangeable lens cameras and SLRs) threaten their business, they decided to not sit idly by. Instead they developed a system that combined a lens mount with a leaf shutter in such a way as to allow this contraption to work on SLRs (i.e. through-the-lens composing and metering) and offered their design to various manufacturers. Deckel‘s invention is known as the Deckel-mount or DKL mount.
However, the setup wherein several manufacturers used the same mount-and-shutter assemblage was not problem free. While a shutter is always central part of any camera, using an integrated leaf shutter-cum-mount makes both the lenses and the camera in many ways only extensions of the mount. Moreover, while every camera manufacturer / lens manufacturer is constrained by the lens mount, those who “own” the mount they use can decide to redesign the mount, but if you do not control the mount …
Voigtländer as part of Zeiss.
Zeiss (West) bought the majority share of Voigtländer in 1956. Zeiss was the one company that did not need to envy Voigtländer’s lens design prowess. Moreover, by this time it was similarly clear that also in the case of Zeiss the lens design and manufacturing business (“Carl Zeiss”) was way more competitive than the camera making (“Zeiss Ikon”). What resulted was a partnership that was plagued by infighting, not-invented-here -thinking and jealously watching out for whatever one perceived as one’s ‘turf’.
The Bessamatic had mostly been designed before the acquisition by Zeiss, and was hence not yet so badly marred by the dysfunctional partnership. Moreover, it was painfully clear that the Bessamatic was more competitive and more up-to-date than the in-house competition (the Zeiss Contaflex). Moreover, as the original 1959 Bessamatic was improved by each subsequent introduction (ending with the Ultramatic CS), there seemed to be real potential in using the Voigtländer designs to manufacture a relatively competitive, broad-spectrum camera that could put up a fight against the onslaught of Japanese SLRs that were now reaching the Europe en masse.
However, the Bessamatic/Ultramatic was really a dead end. The leaf shutter – while certainly not without advantages – was both clunky and expensive, and – most importantly – practically precluded developing any really wide or really bright lenses. Zeiss Ikon and Voigtländer needed a new platform to be able to face down the Japanese manufacturers. Luckily, Voigtländer’s design bureau happened to have plans for just such a camera.
In that story – that of the Voigtländer/Zeiss Ikon Icarex – the dysfunctional partnership came back with a vengeance. I will not repeat that story here (it is detailed in the JAPB data sheets of Icarex lenses, e.g. here), but I will say that it was so bad that Zeiss decided to stop manufacturing cameras altogether and ended up selling what remained of Voigtländer to none other than Rollei. But that’s another story.
Only one version of this lens is known.
To use this lens in its native environment, you will need a Voigtländer Bessamatic or Ultramatic body. While these still exist in comfortable numbers, those numbers are dwindling. Moreover, due to the inherent complexity of the leaf shutter SLR construction, repairs will not be easy to procure.
This lens can be adapted to all mirrorless cameras using a suitable adapter. Because this lens (alike most DKL lenses) does not have an aperture ring of its own, you will need an adapter that allows you to control the lens’ aperture. As the DKL mount was of only moderate popularity, availability of DKL adapters to all mirrorless mounts cannot be taken for granted. On the other hand, one can be strategic with adapters (e.g. DKL->Canon EF; Canon EF –> mirrorless) which also opens up a wide range of special adapters (speed boosters, helicoid adapters, tilt/shift adapters).
While the flange focal distance of the DKL mount would indicate otherwise, using this lens on an SLR/dSLR is also an option (see the DKL mount article to understand why), assuming a suitable adapter can be found/manufactured. As of this writing, DKL to SLR adapters exist for at least the following mounts: Canon EF, m42, Minolta/Sony A, Nikon F, Pentax K.
1 Focal length is (unless stated otherwise) given in absolute terms, and not in Full-frame equivalent. For an understanding of whether the lens is wide/tele, see ‘Angle-of-view’.
2 Picture angle is given in degrees (based on manufacturers’ specs) and concerns the diagonal picture angle. Rule of thumb:
> 90 ° ==> Ultra-wide-angle
70–90 ° ==> Wide-angle
50–70 ° ==> Moderate wide-angle
40–50 ° ==> ‘Standard’ or ‘normal’ lens
20–40 ° ==> Short tele lens
10-20 ° ==> Tele lens
5-10 ° ==> Long tele lens
< 5 ° ==> Ultra-tele lens
3 Length is given from the mount flange to the front of lens at infinity.
4 Diameter excludes protrusions such as rabbit ears or stop-down levers.
5 S=straight; R=rounded; C=(almost)circular at all apertures.
6 In this very good review, the author draws a different conclusion, tracing the Septon’s lineage via the even more fabled Voigtländer Nokton 50/1.5 (likewise for the Prominent camera). My personal, albeit untrained and uneducated, eye would however find it more likely that Tronnier had started with the existing (and not extremely costly-to-manufacture) f/2 design