A photographic lens system for forming an object image is placed in the lens barrel of an electronic camera. A tensioning cylinder is mounted for rotation within a pair of apertures provided, respectively, in the horizontally oriented flanges, the tensioning cylinder formed with a through-slot extending longitudinally between a pair of radial flanges. Therefore, it is possible to adjust the thickness variation of a PCB in real time, as they are being produced, to decrease the number of bad packages. 9 g per unit dtex and having a stretchability of 2. The servo motor has a splined output shaft.