Pro Moviemaker Summer 2018


Behind the lens

Sigma’s technicians had to put in a huge amount of work to build a complete cinema lens line-up

W hen Sigma decided to take the brave step of entering the highly competitive cinema lens market, the company was fully aware of the scale of the task it was taking on. While Sigma Art lenses aimed at the still photographer were widely held in high esteem, with many filmmakers already working with them, the fact is that this was a market dominated by established players and it was always going to be a battle to gain recognition. Key to making the breakthrough was having a full range of lenses to talk about from day one, giving filmmakers the confidence that this was indeed going to be a full-blown move into a fresh area. But for this to happen, Sigma’s army of in-house technicians had to work night and day to design the new bespoke housings that would accommodate the optical line-up from the Art lens range. Each one had to be individually tailored to do its new job without impacting on optical performance, and there was a limited amount of time within which to complete the process. What’s happened since has been a roundly well-received entry into this fresh market, with the full range of Sigma Cine lenses – two High Speed Zooms, one

they are based on don’t have this function, so we had to incorporate rubber seals to the mount and sealing to each ring. Did the fact that the optical set for each lens already existed make the process quicker and easier? Yes it did. The most challenging process during lens development is to achieve high optical performance, and this was already established during the development of lenses for still photography. What were the crucial characteristics that you were looking to incorporate across the whole of the new Cine range? We wanted the lenses to be able to communicate important information such as focal length, shooting distance and aperture, and to enable this we incorporated a circuit board and encoder. These days there is an increasing need to properly record shooting data. The number of crew in the field is becoming less, making it harder to record shooting conditions. Therefore, it’s important that we can record this data automatically. In addition, having the shooting information makes the synthesis process for VFX easier. With lenses for still photography, focusing speed is generally faster at long distances

Full Frame Zoom and seven Full Frame High Speed Primes – now out there in the market and gaining acceptance from a very discerning filmmaking community. But how was this task accomplished and what were the challenges that had to be overcome? We decided to find out directly from Sigma’s Japanese technical team. How challenging was it to design new housings for the existing Art lens optics? The position of each ring and the length and thickness of lenses for still photography are so different from one another. Art line lenses do not have an iris ring, so we started the design from there. With the three zoom lenses we designed them simultaneously and, after finishing them roughly, we adjusted and standardised gear positions, such as the focus, zoom and iris ring. Of course, we didn’t just standardise them but ensured compatibility with cinema cameras and other accessories, such as matte boxes and follow focus units. We also asked cinematographers both from Japan and elsewhere to try our lenses and we took into account their feedback. Furthermore, Sigma’s cine lenses are dust and splash proof. This was a challenge to develop and test since the Art lenses



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