Having attended lens service training at Angenieux, ARRI, Cooke, and ZEISS, learning more about the Leica CW Sonderoptic cine lenses was most welcome. When Osamu Tsukada, Asia Regional Sales Manager of CW Sonderoptic invited me to attend a lens technical service training seminar in Wetzlar, Germany, I did not hesitate.

It was perfectly timed, as the seminar was to take place during the short lull between IBC and Cinec. Wetzlar is a good stopover between Amsterdam and Munich.

 The medieval town of Wetzlar is 45 minutes north of Frankfurt. With an abundance of technical know-how, clean water, fresh air, and exemplary German engineering, it is not surprising that optical giants such as Leica and ZEISS  have major facilities here.

In sharp contrast to its Romanesque and Gothic walls, structures and cathedral, we find Leica’s ultra modern factory, facilities, museum, and Leitz Park III, now under construction. Leitz Park III broke ground in 2016. It will include a new Ernst Leitz Hotel with 120 beds, a new museum that will be part of Leica World and new headquarters for CW Sonderoptic.

https://www.youtube.com/watch?v=EyiyPbaa-aw

Mareike Feiling, CW-Sonderoptic Service Manager, welcomed us to the seminar room. Uli Schröder, Head of Lens Assembly, proceeded to give us with his 38 years lens experience at Leica and CW a quick history of the development of the famed Leica Summilux-C and Summicron-C cine lenses. Some diagrams and written procedures were distributed under NDA.

Leica was able to achieve enviable optical qualities and wide apertures in a small size by utilizing advanced  design, aspherical glass elements, and very precise tolerances.  Consequently, even a trained lens technician can only do partial servicing and disassembly of the lenses at the front of the lens. The mid and rear section, where the aspherical glass elements are very precisely located necessitates the use of sophisticated optical alignment tools.

Using factory-issued tools, Uli proceeded to dissemble the front section of the lens, but warned us again of not proceeding beyond a certain point, which was content of the training level one. Leica’s cam system is unique and admirable—assuring that the 6 feet position is always half of the rotation angle. Also every Summilux-C lens has its own individual focus scale. Then it was our turn to partially disassemble and assemble under Uli’s watchful eye.

After lunch in Leica’s modern cafeteria, Uli proceeded to explain and disassemble the different optical and mechanical parts of the Summicron-C lens. Again Uli mentioned not to go beyond the trained level, as disassembling beyond a certain level will necessitate the lens going back to Wetzlar for precise factory alignment with CW’s special optical equipment. After Uli assembled the different portions from the Summicrons-C, it was our turn to do the same. Luckily, Uli was around to guide us through the process.

It is gratifying to know that CW-Sonderoptic encourages clients’ lens technicians to attend these service courses.