Canon RF 10-20mm F/4 L IS STM Lens

The Canon RF 10‑20mm F/4 L IS STM Lens is a professional‑grade ultra‑wide‑angle zoom lens designed for Canon’s full‑frame mirrorless EOS R‑series cameras, delivering exceptional imaging capability across stills and video applications. With a focal length range of 10–20 mm, this lens provides one of the widest rectilinear fields of view available in the RF mount lineup, allowing photographers to capture expansive landscapes, dramatic architecture, interior spaces, travel scenes, and creative wide‑angle perspectives with confidence.

Optically, the RF 10‑20mm F/4 L IS STM is engineered with a sophisticated 16‑element, 12‑group construction that includes one Super UD (Ultra‑Low Dispersion) element, three UD elements, and three aspheric elements. These advanced optical components work together to reduce chromatic aberration, minimize distortion, and deliver high overall sharpness from center to edge of the frame. Canon’s coating technologies — including Super Spectra Coating (SSC), Subwavelength Structure Coating (SWC), and Air Sphere Coating (ASC) — further suppress flare and ghosting for improved contrast and accurate color reproduction in challenging lighting conditions.

One of this lens’s most important features is its built‑in Optical Image Stabilization (IS) system, which offers up to 5 stops of shake correction on its own. When paired with Canon EOS R cameras that include in‑body image stabilization (IBIS), the coordinated IS system can provide up to 6 stops of combined stabilization, making handheld shooting more reliable in low light and helping smooth video capture.

Autofocus performance is driven by a stepping motor (STM) focus system, known for its quiet and smooth operation. This makes the lens particularly suitable for video recording, where noise‑free focusing and gentle focus transitions are critical. The STM system also enables responsive autofocus in still photography, and the lens supports full‑time manual focus override, giving photographers precise control when needed.

The lens’s design also incorporates user‑friendly handling features such as an assignable Control Ring for direct access to settings like aperture, ISO, or exposure compensation, and a programmable lens function button on the barrel for custom control assignments. A built‑in petal‑style lens hood helps to protect the front element and reduce flare, and a rear gelatin filter holder allows the use of ND or other specialty filters without front‑mounted filter threads.

With a minimum focusing distance of 0.25 m (9.8 in) and a maximum magnification ratio of 0.12x, the RF 10‑20mm F/4 L IS STM is capable of striking close‑to‑subject ultra‑wide compositions that emphasize foreground scale and depth. While ultra‑wide lenses can present challenges such as barrel distortion, especially at 10 mm, modern in‑camera and software corrections help mitigate these effects for practical use.

Despite its robust performance and professional features, the RF 10‑20mm F/4 L IS STM maintains a relatively compact and lightweight design compared to earlier ultra‑wide optics, weighing around 570 g and measuring approximately 112 mm in length. As an L‑series lens, it also features dust and moisture resistance, reinforcing its suitability for demanding outdoor environments and professional workflows.

Overall, the Canon RF 10‑20mm F/4 L IS STM Lens combines ultra‑wide optical capability, advanced stabilization, smooth autofocus, and rugged build quality, making it an excellent choice for photographers and videographers seeking expansive perspectives without compromising image quality or handling.