Canon's compact L-series ultra-wide zoom for RF-mount with IS and constant f/4.
The Canon RF 14-35mm f/4L IS USM was released in 2021 as the wide-angle zoom anchor for the RF L-series lineup, providing a 14-35mm full-frame range with the notable ability to accept standard 77mm screw-in filters at 14mm — achieved by a retractable inner barrel design that allows a flat filter-accepting front element across the zoom range. IS is built in for handheld wide-angle video and landscapes. L-series dust and moisture sealing is built throughout.
The optical design uses 16 elements in 12 groups, including UD and aspherical elements. Nine aperture blades. The 77mm filter thread accepts screw-in filters across the full zoom range. At 540g the lens is compact for a full-frame wide zoom. Minimum focus distance of 0.2m throughout enables ultra-wide close-focus foreground placement. IS is built in. Ring USM provides fast, quiet AF. L-series dust and moisture sealing is built in. Constant f/4 aperture throughout.
The 77mm filter compatibility at 14mm is the RF 14-35mm's key differentiator from many full-frame ultra-wide zooms, which require expensive drop-in systems or no filtration at all due to protruding front elements. For landscape photographers who rely on circular polarisers or graduated ND filters at ultra-wide angles, this capability is directly practical. The 0.2m close-focus enables dramatic wide-angle foreground placement. The f/4 constant aperture is one stop slower than the RF 14-35mm f/2.8L, which doesn't exist.
On the used market the RF 14-35mm f/4L IS USM is available at L-series wide zoom pricing. Condition checks: IS operation, ring USM response, L-series sealing at the retractable barrel, 77mm filter thread for damage, and front element for marks. The Canon RF 15-35mm f/2.8L IS USM provides f/2.8 with the same filter capability. Compatible with all Canon RF-mount bodies.