The Canon RF 24-105mm f/4 L IS USM stands as a cornerstone in Canon's professional RF mirrorless lens lineup, designed as a highly versatile standard zoom for photographers and videographers seeking a single, capable lens for a wide array of scenarios. As an L-series lens, it embodies Canon's commitment to premium optical quality, robust build, and advanced features, making it a compelling option for those invested in the EOS R system.
At its core, the lens offers an incredibly practical focal range of 24mm to 105mm. The 24mm wide end is ideal for expansive landscapes, architectural interiors, and environmental portraits, providing a broad perspective without excessive distortion. As the focal length extends to 105mm, it seamlessly transitions into a portrait-friendly range, capable of isolating subjects with a pleasing compression, and proving useful for events or even modest telephoto applications. This comprehensive range is a significant strength, making the RF 24-105mm an excellent "walk-around" or travel lens, eliminating the need to frequently swap lenses and ensuring that photographers are prepared for diverse photographic opportunities without added bulk.
A defining characteristic of this lens is its constant maximum aperture of f/4 across the entire zoom range. While not as wide as an f/2.8 zoom, f/4 contributes significantly to the lens's manageability, allowing for a more compact and lighter design, weighing in at a reasonable 700g. This constant aperture ensures consistent exposure settings when zooming, a valuable feature for both still photography and video recording, particularly when using a gimbal or during dynamic shooting situations. For many users, particularly in well-lit conditions or when relying on modern camera bodies' impressive high-ISO performance, f/4 is more than adequate. The nine-blade circular diaphragm contributes to a smooth out-of-focus background (bokeh), although achieving extreme subject separation will naturally be more challenging than with faster prime lenses or f/2.8 zooms.
Optically, the RF 24-105mm f/4 L IS USM lives up to its L-series designation. Constructed with 18 elements in 14 groups, including several aspherical elements and a UD (Ultra-low Dispersion) element, it is engineered to deliver high sharpness from edge to edge, especially at wider apertures, and effectively suppress chromatic aberration and distortion. While some minor barrel distortion may be present at 24mm and pincushion distortion at 105mm, these are well within expected limits for a zoom of this range and are often automatically corrected in-camera or during post-processing. Vignetting is also generally well-controlled, particularly when lens profiles are applied. The fluorine coating on the front element helps repel dirt, dust, and smudges, making cleaning easier and enhancing durability, especially in outdoor environments.
One of the lens's most compelling features is its highly effective 5-stop Image Stabilization (IS) system. This is a game-changer for handheld shooting, allowing photographers to capture sharp images at significantly slower shutter speeds than would otherwise be possible. This benefit is especially pronounced in low-light conditions, during travel photography where tripods might be impractical, or when shooting video where smooth, stable footage is paramount. When paired with an EOS R camera body featuring in-body image stabilization (IBIS), the combined stabilization can be even more potent, providing an exceptional level of shake reduction.
The autofocus system, driven by Canon's renowned Ultrasonic Motor (USM), is both fast and quiet. This makes the lens highly responsive, accurately tracking moving subjects for event photography, and performing seamlessly during video recording without introducing distracting motor noise. The minimum focusing distance of 0.45m provides a maximum magnification of 0.24x, allowing for reasonably close-up shots, adding to the lens's overall versatility for capturing details or semi-macro subjects.
In terms of build and handling, the RF 24-105mm f/4 L IS USM exudes professional quality. Its weather-sealed construction makes it a reliable companion for landscape and travel photography in challenging conditions, offering peace of mind against dust and moisture when paired with a similarly sealed camera body. The lens features Canon's customizable Control Ring, a signature element of RF lenses, which can be programmed to adjust various settings like ISO, aperture, or exposure compensation, providing intuitive and quick access to critical controls without taking one's eye from the viewfinder. The 77mm filter thread is a common size, making it easy to share filters with other professional-grade lenses.
This lens truly excels in several use cases. For walk-around and travel photography, its versatile focal range, relatively compact size, effective IS, and robust build make it an ideal companion for capturing diverse scenes from wide vistas to tighter portraits. Landscape photographers will appreciate the 24mm wide end, L-series optical quality, and weather sealing for capturing stunning outdoor scenes. While f/4 is not the fastest, the 105mm end, combined with its optical performance, makes it suitable for portrait photography, offering pleasant background separation. For event photography, the constant f/4 aperture, fast USM autofocus, and image stabilization are highly advantageous in capturing candid moments and dynamic action. Lastly, for video production, the quiet USM, constant aperture, and powerful IS system make it a strong contender for run-and-gun shooting and professional videography.
While the f/4 aperture might be a consideration for those primarily shooting in very dim conditions or requiring extreme shallow depth of field for artistic purposes, the RF 24-105mm f/4 L IS USM presents an outstanding balance of performance, versatility, and build quality. It is a highly capable, reliable, and well-rounded professional-grade standard zoom lens that effectively serves as a workhorse for the Canon RF system, delivering consistent L-series quality across its useful focal range.