Repair - broken aperture ring - Voigtlander 35mm F1.4 II Nokton Classic MC lens Leica M mount

 The lens in this article is provided for repair by Wes McClain (thank you!) and I just received it today. This Voigtlander 35mm F1.4 II Nokton Classic lens is a Multi Coated version, but it has exactly same mechanics as the one I own and was recently disassembling. Though this time I'm going to further explore the aperture ring mechanics area.

Voigtlander 35mm F1.4 II Nokton Classic is quite durable and beautiful little lens. Of course it is not designed to withstand hits and bumps. Leica M camera is relatively heavy and that weight is adding to the power of hit if camera is accidentally bumped facing lens toward the hard surface like concrete wall. If you look closer at image below - there is a large gap between hood mount ring and aperture ring.

There was a significant impact to the lens front and one of aperture ring control blades have noticeable dent on its edge. The aperture ring is very loose and wobbling, however aperture can be still controlled properly. but there are no clicks anymore. Impressively enough there are no other visible damages to lens optics or mechanics, focusing is smooth and precise, image quality remains same as new.

I'm suspecting that the aperture retention brass ring could jump off the place. The aperture click ball may be lost, so a replacement may be needed. Though there is a chance aperture click ball could be still somewhere inside.

At first I'm dismounting optical core form focusing frame by unscrewing CCW retention ring located around rear optical core area. Yes, the retention brass ring is misplaced but looks intact.

I'm accurately extracting retention ring by moving it up-right in spiral direction around optical core cylinder.

I'm also checking that retention ring is flat and can be tightened by holding it firm inside paper notebook.

Then I'm unscrewing two bolts, it takes some effort to break this glue. It's important to memorize each bolt location and assemble it back to same place to fit glue position later. Then I'm removing aperture transmission.

Now aperture ring can be pulled out. I'm glad to see that click ball is not missing. Fortunately it travelled to another place - a hole of hood mount ring bolt located form the opposite side.

I'm use set of powerful magnets to extract metal ball.

Then I'm accurately locating metal ball to its original place - spring loaded hole below the side pin on optical core.

Next step is to accurately move back brass retention ring. Helicoid sliding slots are protruding wider than ring internal diameter, so I'm moving it back in spiral direction. It's similar to how you mount keys to spiral key ring. After securing retention ring I'm fitting back aperture transmission and screwing in two bolts, red glue on bolt head fits the glue part that remains on transmission. Then I'm checking that aperture clicks work as expected.

Then I'm attaching lens core to focusing frame. Unlike in previous disassembly article I'm not using blue putty. This time I decided to cut thin strip of rubber.

Then I'm wrapping rubber strip around optical core on top of retention ring edge.

I'm using that pills container and pressing firm on rubber strip, then rotating retention ring in CW direction until it sits firm. Done, lens is assembled and ready to get packed and sent back to its owner.

Conclusions

Further disassembly of Voigtlander 35mm F1.4 II Nokton Classic aperture ring mechanics shows that access is relatively simple if you have right tools and skills. This repair takes very little effort and time. I'm impressed by lens overall durability and how well aperture-click mechanics is organized, so it can be maintained with minimal number of assembly steps.

If you by any chance like using lens with click-less aperture, it's possible to permanently remove ball and clicks will disappear. Though in many cases Voigtlander lens owners are frequently utilizing aperture clicks on Rangefinder cameras by counting them to know which aperture value is set without looking at lens. It allows to keep looking through viewfinder and focus on picture composing.