What’s New: RF 24–240mm F4–6.3 IS USM
July 8, 2019
Lightweight and compact, the Canon RF 24–240mm F4–6.3 IS USM is the first extended-range zoom for Canon’s EOS R-series cameras, and will be an ideal travel companion for Canon EOS R and RP cameras. We’ll look at some of the special features and capabilities of the 24–240mm lens that make it noteworthy not only as a standard zoom for still imaging, but for video recording as well.
For some users, the 24–240mm lens may be the perfect way to enter the full-frame, mirrorless Canon EOS R system. The 10x zoom range gives it outstanding versatility, giving photographers a lens which can handle scenes as varied as landscapes, portraits, close-ups, and even many sporting applications.
The RF 24–240mm F4–6.3 IS USM will be available individually, as well as sold in kit form with the compact EOS RP camera.
Portability and handling
The RF 24–240mm lens is the lightest 10x zoom lens for full-frame digital cameras from Canon to date, weighing-in at approximately 26.5 oz. (approx. 750g) — about the same as Canon’s EF 70–200mm f/4L IS II lens. This is an easy lens for most photographers to hand-hold, even at relatively slow shutter speeds. And, its zoom and focus/control rings have a smooth, solid tactile response to the user’s inputs. It’s an especially good match with the compact EOS RP camera, giving users a full-frame camera package capable of strong wide-angle and telephoto framing — a one-lens solution to many types of shooting.
A broad zoom ring is the primary control on this lens, located on the forward section of the lens, near where a photographer’s left hand would typically rest. Zooming is an extension system, with the front optics of the lens moving forward as the lens is zoomed toward its 240mm telephoto position. Although the zoom action is relatively firm, there is a sliding lock switch on the lens, to lock the lens at its shortest, 24mm position, to prevent inadvertant lens movement during transport.
This lens is an excellent partner for video with EOS R-series cameras. Its broad 10x zoom range is especially useful for video users, enabling quick framing changes from one clip to the next without having to change lenses. Two features, in particular, make the RF 24–240mm lens a strong performer for video recording:
- Nano USM focus motor
The super-compact Nano USM focus drive motor is superbly suited for video operation. It’s not only quick and nearly silent, but in particular, its focus movements are extremely smooth — an important consideration for AF operation when a major focus change (foreground to background, for example) is needed during actual recording.
- Optical Image Stabilization with Dynamic IS
The 24–240mm is the first Canon lens for full-frame cameras with Dynamic Image Stabilization. In addition to the 5-stop IS correction which operates during still image recording, the Dynamic IS adds a second type of correction, for the larger, lower-frequency types of movements that often happen during video recording. A perfect example is if a user is recording while walking, following a moving subject — Dynamic IS can minimize the large movements that can occur in these circumstances.
Combination Manual Focus ring and Control Ring
The second, smaller ring (closer to the lens mount) on the RF 24–240mm lens is the Focus/Control Ring. A sliding switch on the left side of the lens lets the photographer decide whether rotating this ring will provide Manual Focus control, or Control Ring operation.
For Control Ring operation, this ring’s rotation is stepless, without click-stops during rotation. Otherwise, the Control Ring concept is carried out in the same fashion as previously-introduced Canon RF lenses — the user can determine which exposure adjustment (ISO, shutter speed, aperture, or Exposure Compensation) is adjusted by rotating the Control Ring. And while actual rotation is without click-stops on this lens, the exposure function in question continues to be changed in the same number of steps as before. (For example, shutter speed would normally be varied in 1/3-stop increments, via the Control Ring.)
Manual Focus operation
Sharp-eyed users will note that there’s no “AF/MF” switch on the lens barrel. When the sliding switch on the lens is set to “FOCUS,” rotating it will provide Manual Focus — but the following operational rules apply:
- Total Manual Focus operation:
To completely by-pass Autofocus, the user must set the Focus Mode to “MF” in the camera’s Menu. This would allow traditional Manual Focus operation, such as when shooting fireworks, working in controlled conditions with a tripod, and similar circumstances.
(With the 24–240mm lens attached, this appears in the purple-colored AF Menu on the EOS R camera, and in the red Shooting Menu on the EOS RP camera.)
- Full-time Manual Focus:
This means AF shooting, but with Manual Focus available by turning the Manual Focus ring on the lens, without going into the camera’s menu to switch it from AF to MF. Canon SLRs have had this feature for decades, with many of the USM-type EF lenses.
Two ways to achieve this, with the EOS R and RP cameras — with the switch on the side of the RF 24–240mm lens set to “FOCUS”:
- In One-Shot AF, use AF to focus upon your subject (via either the shutter button, or rear AF-ON button). Once the camera confirms AF is correct, hold down the focus activation button — while holding it down, turn the Focus ring.
- With the camera set for “Back-button AF” (AF via the AF-ON button… AF removed from the shutter button in the camera’s Custom Controls) and the EOS R/RP Menu set for AF, use the AF-ON button for any and all AF operations. Remove your thumb from the AF-ON button, turn the Manual Focus ring, and you immediately have Manual Focusing.
This is a strong lens optically, with a 21-element design. It’s highlighted by an Aspherical lens element, and two UD (Ultra-low Dispersion) glass elements, to suppress chromatic aberrations. It takes advantage of the fundamental mirrorless design of the Canon RF mount, utilizing a large-diameter rear optical section, which permits the forward part of the optical design to be smaller in size, without dropping performance.
Focusing is via a rear focus mechanism, with only a small group of internal optical elements moved to change focus.
The RF 24–240mm F4–6.3 IS USM lens’ minimum focus does shift, depending upon the zoom setting (more in a moment). But as with most zoom lenses, when looking to fill the frame with a small subject, you’ll get maximum magnification with the zoom set to 240mm, and the nearest focus distance.
Maximum close-up magnification is 0.26x — a tiny bit beyond 1/4th life-size magnification, and giving users the ability to fill the frame with a subject smaller than a US dollar bill.
Minimum focus distances:
- 24mm — 1.64 feet (0.5m)
- 240mm — 2.56 feet (0.78m)
Again, maximum close-up performance, in terms of frame-filling magnification, will be at the 240mm zoom position.
Even greater close-up performance is possible with the optional 72mm Canon Close-up Lens 500D, which can provide magnifications up to 0.57x.
The lens uses 72mm screw-in filters; there’s an optional bayonet-mount Canon Lens Hood EW-78F available as an accessory; and the lens is 4.82 inches (122.5mm) in length.
The RF 24–240mm F4–6.3 IS USM lens is an important addition to the Canon EOS R line-up, giving users a versatile, solid extended-range standard zoom lens. It will clearly be of interest to advanced amateur users, and even the quality-conscious casual amateur, for its ability to offer a one-lens solution for travel and so many other types of photography. And, its video capabilities further enhance the 4K and Full HD recording capabilities of EOS R and RP cameras.
Combined in kit form with the EOS RP, this is a particularly appealing potential package, for photographers looking to make the move into a full-frame camera. And, even for more advanced EOS R-system photographers who may rely on some of the superb-quality L-series lenses initially introduced in the Canon RF lens line-up, the 24–240mm offers a pleasing and high-quality alternative for many different shooting scenarios.
All Canon contributors are compensated and actual users of Canon products promoted.