The Canon RF 400mm F2.8L IS USM and RF 600mm F4L IS USM lenses are the perfect choice for wildlife, sports and press photography. With their lightweight design, weather-resistant construction and rich image quality, they deliver exceptional images in the toughest conditions.
Although they share much the same optics, mechanics, electronics and firmware as their EF stablemates (the Canon EF 400mm f/2.8L IS III USM and EF 600mm f/4L IS III USM), the RF versions of these classic lenses have a key advantage: the RF mount itself. With 12 electrical contacts – four more than the EF mount – communication between the camera and the lens is much faster and higher-bandwidth, unlocking a new level of performance.
Motorsports photographer and Canon Ambassador Vladimir Rys recently got to grips with the two RF super-telephoto lenses on a rally car shoot with the Canon EOS R3. Vladimir is no stranger to the EOS R System, as he usually uses a Canon EOS R5 – paired with either a Canon RF 50mm F1.2L USM lens or a Canon RF 85mm F1.2L USM – alongside his Canon EOS-1D X Mark III when covering events.
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Life in the fast lane with Canon's super-telephoto lenses
"Weight-wise, the RF lenses are similar to their EF counterparts," Vladimir says, "but their speed is impressive. The RF lenses were faster to use, with the autofocus and the image stabilisation feeling much more precise. The RF mount allows for so much more data to be transferred in a short period of time, and this faster communication between the lens and the camera really does make a difference when you're shooting."
Mike Burnhill, Professional Imaging Product Specialist at Canon Europe, explains that the enhanced autofocus speed with the Canon EOS R3 is down to Dual Power AF. "These two super-telephoto lenses are the first to need the dual power supply," he says. "The optical groups in these lenses are much larger than those used in other lenses, so we drive them with large, high-torque, ring-type USM motors. There are actually two power inputs into these motors. The more power you feed into the motor, the faster it turns, and therefore the faster the autofocus speed can be."
The Canon EOS R3 is the first EOS R System camera that can take full advantage of lenses with Dual Power AF, thanks to its more powerful LP-E19 battery pack. "You need more voltage to drive the motor, which would have had too much impact on the battery life of earlier EOS R System bodies," explains Mike.
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Improved IS through the RF mount
In addition to making light work of autofocus, the Canon RF 400mm F2.8L IS USM and Canon RF 600mm F4L IS USM are nimble when it comes to handling. They might be the biggest lenses in the RF range, but for this class of super-telephoto lens they are extremely portable – close to being the lightest on the market.
Both RF lenses come with built-in optical IS that provides 5.5 stops of protection against camera shake – a half-stop improvement over the EF lenses. Once again, that gain in performance is down to the RF mount. "There's a feedback loop between the camera and the lens, so the gyroscopes in the body and the sensor contribute to the IS system," explains Mike.
"The lens is doing all of the work, shall we say, but the sensors that feed into the process are controlled through the RF mount in the body. The RF mount communicates multiple times faster than the EF mount, so it's possible to get that extra vector data into the system and increase the IS capabilities by half a stop as a result."
Vladimir welcomed the light weight and IS advantage, particularly when working with the Canon RF 600mm F4L IS USM. "The lens is so light that it's perfectly possible to do some handheld shots with it," he says. "I was using a monopod most of the time, though, as it's just easier on a longer shoot."
During his three-day rally commission, Vladimir focused on freezing the car at high speeds using the EOS R3's groundbreaking shutter speed, frame rate and advanced autofocus. But he also took the camera and the RF 600mm F4L IS USM to the Formula 1 British Grand Prix at Silverstone, where he could experiment with panning shots at slower shutter speeds. "If you're shooting, let's say, a half-second pan handheld, the stabiliser helps massively," he says.
Lens corrections at 30fps
The RF super-telephoto lenses deliver the kind of top tier image quality that you'd expect from L-Series prime lenses. "I've been impressed with their colour transmission," says Vladimir. "I normally use the Canon EF 400mm f/2.8L IS III USM on my Canon EOS-1D X Mark III. Obviously, that's a different sensor to the one in the EOS R3, but the richness of the colours and the level of detail were incredible with this new combination of camera and lens. I was only shooting JPEGs, but the outcome was so close to RAW that I couldn't really see any difference when I was editing the pictures."
Even compared to their highly regarded EF counterparts, the RF super-telephotos deliver even better image quality. Once more, that's down to the benefits of the high-speed RF mount. "It's the DLO processing that makes the difference," says Mike. "Each RF lens has its own profile built into it. This contains all the data related to potential problems that couldn't be eradicated through the optical design, as well as diffraction patterns for different apertures, and so on.
"The camera can access this information on the fly, enabling the DLO processing to be applied as you shoot without any impact on performance. This means that, with the Canon EOS R3, you're able to shoot at 30fps and still benefit from the correction of lens aberrational data and diffraction values."
Using the Canon EOS R3's amazing Eye Control AF
Longest and widest RF L-Series lenses
As well as putting the longest RF L-Series lenses to the test, Vladimir also went to the other extreme, trying out the ultra-wide Canon RF 14-35mm F4L IS USM. The widest lens available for the EOS R System offers a vast angle of view of up to 114° and completes the F4 trinity of Canon RF zooms.
"I prefer working with prime lenses," says Vladimir. "But sometimes you have no time to change a lens. The Canon RF 14-35mm F4L IS USM produced one of my favourite images from the rally shoot – a landscape shot with the car kicking up dust in the foreground. I was amazed by the colour and sharpness – the sky was so rich, and the textures were crisp. The light helped a lot, but the coatings on the new lens clearly played a part."
According to Mike, the Canon RF 14-35mm F4L IS USM features a new optical design that maximises image quality. "The lens includes three aspherical and two UD lens elements, plus an additional optic that is actually a mix of aspherical and UD. That's quite unusual, as normally it's either one or the other. But here, the combination helps us to maintain the quality while reducing the size of the lens.
"It's a lot lighter and more compact than the Canon RF 15-35MM F2.8L IS USM, but it also benefits from a half-stop improvement in image stabilisation, and it's obviously wider as well. A 1mm difference doesn't sound a lot, but that small improvement can make quite a big difference to users. There's always a balance between performance and size, but sometimes a slower lens really can outperform the faster lenses."