The Canon RF mount is pretty well established now, with plenty of optical options for photographers looking to capture different fields of view. However, that doesn't mean that the imaging giant is resting on its laurels. A recent patent application from Canon shows that we could potentially be expecting some ultra ultra-wide zoom lenses for the RF mount at some point in the future.
It's worth noting that Canon is renowned for firing off patent applications left, right and center, so there's no guarantee that these ultra wide angle zooms will ever see the light of day. However, it's certainly not beyond the realm of possibility that Canon will pursue at least one of the designs it's patented.
• Read more: Best Canon RF lenses
This latest patent application has been reported on by Canon News, which suggests that these new designs would be a "halo lens" that's similar to the Canon EF 11-24mm f/4 L, which features a bulbous front element.
The designs featured on this new patent application include a Canon RF 10-17mm f/4 and two slightly different Canon RF 9-17mm f/4 designs. There are also two designs that likely wouldn't be suitable for the Canon RF mount – a 9-24mm f/4 and an 8-16mm f/4. According to Canon News, these last two lenses probably wouldn't fit on the RF mount "given the amount of ingress into the mount these designs are asking for".
The widest Canon lens is currently the Canon RF 15-35mm f/2.8L IS USM and there aren't any wider lenses currently expected in the Canon RF lens roadmap, so there's definitely scope for Canon to explore wider focal lengths in their upcoming range of glass.