Canon RF 800mm f/11 IS STM Lens

The Canon RF 800mm f/11 IS STM Lens is a super-telephoto prime lens designed for Canon’s full-frame RF-mount mirrorless cameras, offering extreme reach in a surprisingly portable package. With its fixed 800 mm focal length, this lens lets photographers capture distant subjects — such as wildlife, birds, sports, aviation, and landscapes — without sacrificing portability or ease of use. Despite the long focal length, Canon engineered this lens to be relatively compact and lightweight compared to traditional super-telephoto optics, making it accessible to enthusiast shooters and travel photographers alike.

Optical and Mechanical Design

At its core is a fixed f/11 aperture, which helps keep the lens’s size and weight down while still delivering good depth of field and optical performance at long distances. The lens uses 11 elements in 8 groups, including gapless dual-layer diffractive optics (DO) that reduce chromatic aberrations and spherical aberrations, helping preserve sharpness and clarity across the extremely long focal distance.

A standout feature of the RF 800mm is its retractable/extendable lens barrel with a locking mechanism. When not in use, the lens collapses significantly to reduce its physical length, making it easier to transport and store in gear bags. When extended into shooting position, it locks securely in place — a practical feature for a lens of this size.

Autofocus and Controls

Autofocus is powered by a Stepping Motor (STM) system that provides smooth, quiet, and reliable focus performance suitable for both still photography and video recording. While the STM design isn’t as fast as some professional USM systems, it strikes a strong balance between performance and noise suppression — particularly useful when capturing wildlife or filming with minimal distraction.

The lens also includes a configurable Control Ring that allows direct access to key camera settings such as aperture, ISO, or exposure compensation without having to navigate menus — a convenient feature for fast-paced shooting situations.

Image Stabilization

To address camera shake — which becomes more noticeable at extreme telephoto lengths — the RF 800mm features built-in Optical Image Stabilization (IS) capable of up to 4 stops of shake reduction, based on CIPA standards. This helps produce sharper handheld images when shooting slower shutter speeds or in less than ideal lighting. When mounted on bodies with In-Body Image Stabilization (IBIS), coordination between lens and camera stabilization further enhances shake control.

Use Cases and Performance

Because of its extreme reach, this lens excels in scenarios where subjects are distant and difficult to approach. Wildlife photographers can fill the frame with birds and animals from afar, while sports and aviation photographers can capture action occurring far from the camera. The fixed f/11 aperture means that shooting in bright daylight works best; in low light, photographers may need to use higher ISO values or faster shutter speeds to avoid motion blur.

Portability and Practicality

One of the most compelling aspects of the RF 800mm f/11 is how Canon has balanced reach with portability. Weighing approximately 1,260 g (about 2.77 lb) and with a retractable barrel design, the lens remains more manageable than traditional super telephotos of similar reach. Its 95 mm filter thread supports standard filters, and it’s compatible with Canon’s RF teleconverter extenders — such as the 1.4× or 2× RF extenders — to increase the effective focal length to 1120 mm or 1600 mm for even more distant subjects.

Summary

The Canon RF 800mm f/11 IS STM is a specialized lens that brings extreme telephoto capability to mirrorless shooters in a lightweight, portable, and affordable form compared to traditional super telephoto designs. Its combination of long reach, optical stabilization, manageable size, and smooth autofocus makes it an appealing choice for enthusiasts or professionals seeking to capture distant wildlife, sports, aviation, and nature scenes — especially in bright outdoor conditions where an f/11 aperture is less of a limitation.