14 DAY TRIAL // The Canon EF-S mount is not the same with the usual EF lens mount and it's usually found on all Canon DSLR camera released after 2003. Although EF-S mount cameras are backward-compatible with EF lenses, this mount allows the optic's elements to be closer to the sensor than the latter.
Japanese website Egami has recently discovered a Canon patent that shows a new EF-S 17-55mm f/3.5-5.6 STM lens as well as an EF-S 18-55mm f/3.5-5.6 STM optic, designed for APS-C format digital SLR cameras.
The new 17-55mm lens comes with a simple construction without any special glass elements, meaning that this could be the next kit lens for Canon's upcoming entry-level digital SLR camera models.
Canon files thousands of patents every year, but that doesn't mean all will reach mass production anytime soon. For the moment, it's not clear whether this optic will replace the current 18-55mm kit lens or not.