Square filters with the Voigtländer 12mm f/5.6 Aspherical II VM lens? Yes, you can!

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A bit of introduction

There’s no secret I’m a fan of wide or extreme wide-angle lenses like every other landscape photographer out there. I love how extreme angles enable unique compositions that literally pull the viewer into the scene. They have their drawbacks, of course, and a quick search on the Internet will return tens of good articles and reviews detailing their pros & cons.

My search for an extreme wide-angle lens to use for my landscape photography brought me to the Voigtländer Ultra-Wide Heliar 12mm f/5.6 Aspherical II VM lens. I won’t detail here the whole rationale behind this choice, which I personally found to provide the best balance between a series of factors like weight & size, character, build quality, price and adaptability to my Sony a7 III camera body. To those of you interested in learning more about it, I wholeheartedly recommend the review written by Bastian Kratzke on phillipreeve.net. However, unlike Bastian, I have gotten my hands onto the 2nd version of this lens, which has a fixed lens hood and accommodates only 67mm circular filters.

As I already use several 100mm square filters from Formatt-Hitech in combination with the Kase K9 holder, there was very little incentive for me to start looking into circular filters for the 12mm Voigtländer. I also use a lot the graduated neutral density (GND) filters in my work, for which the circular variants are too limited. Therefore, I started looking into ways of mounting my K9 filter holder onto the 12mm Voigtlander, all of that without vignetting, of course!

One way to do so was to operate onto the lens by cutting or otherwise removing its fixed hood to enable the use of a 67mm step-up ring to safely mount the holder. Fellow photographer Vieri Bottazzini has performed a similar type of “surgery” on his 15mm Voigtländer and has described the whole procedure in this excellent article. However, I must admit I could not persuade myself to put the fine lens under the saw, so the only remaining option was to look for ways that preserve its integrity.

My next attempt was to fit a 77mm ring onto the exterior of the petal hood. As both the hood and the ring had the same diameter, the hood wouldn’t pass through the ring’s thread. A larger ring of 82mm was therefore required, together with the means of filling in the gap between its thread and the hood. Luckily, the solution appears to be easier than originally thought, involving only common materials and a bit of trial and error.

The solution

My solution involves building a soft ring that fills in the space between the lens hood of the Voigländer Ultra-Wide Heliar 12mm Aspherical II VM and the 82 mm adapter ring of the filter holder, keeping the filter assembly in place using friction. The ring has to fit snugly and without play onto the hood and allow the 82mm adapter to fit securely on top of it.

I opted to build this ring out of black elastic band of roughly the same width (~15mm) as the hood itself, to avoid interfering with the operation of the lens aperture ring. Here is how I did it.

  • To make sure that the band sits tight onto the lens, I wrapped it tightly around the hood until its outside diameter reached approximately 81mm.
  • As I wrapped it, I also applied drops of glue every 2 cm onto its exterior surface, so that the next layer would stay in place while retaining enough elasticity. Taking into account the thickness of the band, I estimated that 3 layers would be needed, but ultimately I could not go for more than 2.
  • Since with 2 layers the band was just below the thickness required to hold the 82mm adapter ring in place, I wrapped its exterior with additional layers of insulation tape, until reaching the right diameter. The smooth insulation tape also allows the adapter ring to be mounted or unmounted on top of the band via the same rotating motion that would normally fit it onto a lens thread, and prevents light leaks coming from behind the camera from hitting the filters.

Testing in the field

I had the chance to recently use my home-made adapter during a city photography session in the beautiful Eilandje neighborhood of Antwerp and I am pretty happy with the results.

Placing the elastic band on top of the camera lens hood went pretty smooth (I got it right on the second try). Due to the shape of the lens hood petals, it may be a bit difficult to wrap the elastic around all four of them at once, so you need to start from one side and gradually pull the band onto the remaining petals. It may simpler to first push the elastic completely beyond the hood and then pull it backwards on top of it, as the tapered back of the hood would make things easier; however, doing so may inadvertently mess up with the aperture and focus rings of the lens, so I’m not a big fan of this idea.

The adapter ring of the filter holder was much easier to place by gently screwing it on top of the elastic band and ensuring that both the adapter and the band align nicely with the top of the lens hood, to avoid any vignetting. The holder sat firmly in place and as I pushed the filter into its slots I felt no wobbling or signs that it would come loose.

Safety first: I do recommend extra care and double-checking that everything is properly in place in order to avoid causing any damage to your filters. For further safety, you shouldn’t carry your camera around with the filter holder on while using this solution, nor should you use it in places with strong wind or above other people, where a falling part could cause injury to others.

Conclusion

I am pretty happy with the described approach as it allows me to use my standard 100mm filter set with the ultra-wide 12mm Voigtländer lens in the same way I use it with all my other lenses. Long exposure and exposure balancing using graduated filters becomes possible and can lead to exciting results considering the extreme 121 degree angle captured by this lens.

The other point I’m happy about is the complete lack of mechanical vignetting. The Voigtländer Ultra-Wide Heliar 12mm f/5.6 Aspherical II VM has a relatively strong vignetting of its own and using the Leica VM version with a non-rangefinder sensor makes it slightly worse, but luckily it all stops here.

To illustrate what I mean, I’m adding below a comparison of the picture shown on the screen of my camera in the previous gallery, before and after processing. If you would like to see more shots taken with this lens and filter combination, please check my post entitled “An Evening By”.

Is this a flawless solution? Definitely not. I wouldn’t trust the soft ring, which uses friction alone to keep the filter holder in place, in the same way that I would trust a standard filter thread or a magnetic mount. But if handled with care, it expands the use of this lens into areas where few other 12mm lenses venture.

Thank you for reading my post, I hope you found it useful. I’ll be happy to hear from you so drop me a line in the comments section if you have any remarks or questions or share it with other folks that may find it interesting!

Disclaimer: I am not associated in any way with the brands mentioned in this post. I do make use of several of their products, which I have chosen and purchased myself based on my own needs and field experience.