S-R2060 Development story
3 : Uncompromising Video Performance and Meticulous Attention to Details for Both High Design Quality and Excellent Operability
Date : 2021.06.16
o suppress focus breathing, the focal length of the focus lens group must be optimized during the optical design stage. For the S-R2060, we opted to configure the second zoom component with four lenses in order to give more flexibility for the optimization of the focal length. This enabled us to successfully optimize the focal length of the focus lens group without destroying the symmetry of the overall optical system. As a result, we have reduced focus breathing to a level that causes no problem even in cinema applications while appropriately correcting various aberrations generated by the entire optical system.
As part of improving the video performance, we also worked on reducing the operating sound of the focus unit and aperture unit during video shooting. Both units are driven by stepping motors operated by the high-precision micro-step control using smooth acceleration/deceleration profiles to realize quiet operation for comfortable video shooting.
In addition, the aperture drive (change of F value) control is smooth even if the brightness of the subject changes significantly or during panning in video shooting. This suppresses noise and sudden change of exposure.
As for the external design, we had to add a “constriction shape” on the outer circumference of the lens barrel as an icon of the S series concept and to improve the ease of operation. However, the zoom ring, focus ring and AF-MF selector switch had to be installed to the circumference of the S-R2060’s small lens barrel, so it was an extremely difficult task to arrange all of them neatly on the compact lens barrel without adversely affecting the apparent size or the ease of operating the rings and switch.
We produced multiple samples of the constriction shape with different ridge heights and width dimensions according to the external lens shape and checked the appearance and operational ease of each sample repeatedly to determine the optimally balanced constriction shape.
The rings must be precision-engineered since they are frequently used in all types of shooting situations, regardless of whether taking pictures or shooting a video. They must move smoothly when the user starts turning it as well as when the user continues turning. They must stop firmly when the user stops turning. Once the rings are positioned, they must not move accidently until they are operated again. Furthermore, the quality of operating feel is an important factor demanded by the customers.
Accomplishing all those requires the improved precision for the inside and outside diameters of each ring sliding section and their clearances as well as the strict selection and management of appropriate grease type, application amount and application method. With the S-R2060, we have achieved a high-quality, silky operating feel and high-precision operation by ensuring dimensional accuracy, by selecting the most appropriate grease specifications and by strictly managing them with the cooperation of the designers and the engineers at the manufacturing plant.