On 14 April 2021, Canon announced the RF400mm f/2.8L IS USM and RF600mm f/4L IS USM, its first professional grade super telephoto prime lenses for the RF mount. 400mm and 600mm prime lenses are staples in sports, wildlife, and bird photography, and no lens lineup is complete without them. The release of native RF mount versions, much anticipated by enthusiast and professional photographers in these genres, is testament to Canon’s commitment to creating a well-considered camera ecosystem. We take a closer look at the key features of these two lenses.

 

The RF400mm f/2.8L IS USM and RF600mm f/4L IS USM are Canon’s first red-line (L-series) super telephoto prime lenses for the RF mount. 400mm and 600mm lenses are go-to lenses for many sports photojournalists, as well as wildlife, bird, railway, and aviation photographers, providing the reach crucial for capturing their subjects. The release of native versions for the RF mount paves the way for a seamless switch to the EOS R system, removing the need for a mount adapter.

What to look forward to

• - Excellent optical performance in a light body
• - Up to 5.5 stops' optical IS
• - Excellent AF; full-time manual focusing in Servo AF
• - Improved video shooting functionality
• - Support for extenders
• - Professional-grade durability and reliability
• - Key specifications
• - Sample images

 

Continuing the heritage of excellent optical performance in a lighter body

Both the RF400mm f/2.8L IS USM and RF600mm f/4L IS USM inherit the optical and mechanical design as the EF400mm f/2.8L IS III USM and EF600mm f/4L IS III USM, which went on sale in December 2018, adapting them for the RF mount. The two EF lenses were highly acclaimed, boasting significant weight reductions and improvements in optical quality over their predecessors (the Mark II models), thanks to the use of new design simulation technologies.

The RF400mm f/2.8L IS USM and RF600mm f/4L IS USM each incorporate two fluorite lens elements and one Super UD lens element. These thoroughly correct chromatic aberration and achieve excellent rendering and contrast, making them capable of impressive close-up shots even at their respectable focal lengths. The application of Canon’s own Air Sphere Coating (ASC) effectively keeps ghosting and flaring under control, even when a strong light source is in the frame—a quality that comes in handy for scenes such as motorsports when vehicle headlights are on.

RF400mm f/2.8L IS USM

EOS R5/ RF400mm f/2.8L IS USM/ FL: 400mm/ Aperture-priority AE (f/2.8, 1/3200 sec)/ ISO 200/ WB: Daylight

RF600mm f/4L IS USM

EOS R5/ RF600mm f/4L IS USM/ FL: 600mm/ Manual exposure (f/5.6, 1/2000 sec)/ ISO 200/ WB: Auto

 

Handhold with ease with up to 5.5 stops’ optical image stabilisation

Whether it is sports or wild birds, the subjects that you usually shoot with a super telephoto lens tend to be on the move and easier to follow by hand. Yet, camera shake is visible at longer focal lengths. But with the RF400mm f/2.8L IS USM and RF600mm f/4L IS USM, there’s no reason to hesitate. The lenses offer up to 5.5 shutter speed stops’ equivalent optical (in-lens) image stabilisation (Optical IS), which significantly reduces camera shake, making it easier to achieve successful shots.

 

Both images: EOS R/ RF400mm f/2.8L IS USM/ FL: 400mm/ Manual exposure (f/2.8, 1/8 sec)/ ISO 400/ WB: Auto

 

3 IS modes to cater to different scenes

Like EF-mount super telephoto lenses, the RF400mm f/2.8L IS USM and RF600mm f/4L IS USM feature three IS modes that optimize IS performance for different types of subjects and scenes.

 

When either lens is attached to a camera with in-body image stabilisation (In-Body IS) such as the EOS R5 or EOS R6, angular camera shake is corrected by the Optical IS whereas shift and rotational camera shake are corrected by the In-Body IS, achieving five-axis image stabilisation.

EOS R5/ RF400mm f/2.8L IS USM/ FL: 400mm/ Manual exposure (f/2.8, 1/15 sec)/ ISO 6400/ WB: Auto

 

Excellent AF control; supports MF fine-tuning during Servo AF

As the RF400mm f/2.8L IS USM and RF600mm f/4L IS USM are equipped with high-performance in-lens microprocessors, they are capable of high-precision focusing motor control. This, combined with improved coordination with the AF algorithm on the camera end, makes it possible to achieve faster, more precise AF.

Full-time manual focusing functionality during Servo AF*, which was available only on demand on the EF versions, is supported straight out of the box, allowing any user to make fine adjustments to focal position with MF regardless of whether they are in One Shot AF or Servo AF mode. Users can enjoy the best of both worlds: the precise AF and subject tracking of the EOS R system, along with the option to take control and adjust focus manually according to their intuition.

*Not supported on EOS R/RP/Ra. Update to Firmware version 1.3.0 or later required on the EOS R5/R6.

EOS R5/ RF400mm f/2.8L IS USM/ FL: 400mm/ Manual exposure (f/8, 1/640 sec)/ ISO 100/ WB: Daylight

 

 

A focusing ring with customisable operational feel

By default, the electronic focusing ring moves the USM (ultrasonic motor) and drives the focusing unit according to the rotation degree of the ring. This enables easy, intuitive MF by using the appropriate torque. It also allows users to select from three levels of focusing sensitivity (how much the focus position moves in relation to the degree of rotation), catering to different requirements for manual focusing speed and precision.

While the lenses have no physical control ring, the focusing ring can be assigned control ring functions on cameras whose interface support such customisation.

 

A force to reckon for video shooting

The EOS R series cameras are meant for more than still shooting—as the 8K video capabilities of the EOS R5 demonstrate, they are also equipped with excellent video capabilities.

The RF400mm f/2.8L IS USM and RF600mm f/4L IS USM are designed to allow users to better harness these video capabilities. One example is in their capacity for finer exposure control during video shooting, where the shutter speed is usually fixed, leaving the aperture setting as main way to adjust the exposure of frames, making them brighter or darker. However, the usual 1/3-stop increments of adjustment is too sudden for video. The RF400mm f/2.8L IS USM and RF600mm f/4L IS USM support aperture control in 1/8 stop increments in movie shooting mode, thus enabling brightness to be changed seamlessly.

 

 

Extend your reach: Support for Extender RF 1.4x/ 2x

Both the RF400mm f/2.8L IS USM and RF600mm f/4L IS USM support the Extender RF 1.4 x and Extender RF 2x, which extend the focal length of the master lens by 1.4x and 2.0x respectively. This takes the focal length of the RF400mm f/2.8L IS USM to 560mm and 800m, and the RF600mm f/4L IS USM to 840mm and 1200mm, achieving even greater reach for scenes where it is necessary.

 

 

Professional-grade durability and reliability

 

 

RF400mm f/2.8L IS USM

 

Lens construction

A: Fluorite lens elements / B: Super UD lens elements / C: ASC
Smudge-resistant fluorine coating on the front and rear lens surfaces

Key specifications

Lens construction: 17 elements in 13 groups
Closest focusing distance: 2.5m
Maximum magnification: 0.17x
No. of aperture blades: 9 (circular blade)
Filter diameter: 52mm (drop-in filter)
Size: φ163×367mm
Weight: approx. 2,890g

 

RF600mm f/4L IS USM

 

Lens construction

A: Fluorite lens elements / B: Super UD lens elements / C: ASC
Smudge-resistant fluorine coating on the front and rear lens surfaces

Key specifications

Lens construction: 17 elements in 13 groups
Closest focusing distance: 4.2m
Maximum magnification: 0.15x
No. of aperture blades: 9 (circular blade)
Filter diameter: 52mm (drop-in filter)
Size: φ168×472mm
Weight: approx. 3,090g 

 

Bundled accessories

 

 

 

Other accessories (sold separately)

 

 

 

Sample images

EOS R5/ RF400mm f/2.8L IS USM/ FL: 400mm/ Aperture-priority AE (f/2.8, 1/1600 sec)/ ISO 200/ WB: Daylight

EOS R5/ RF400mm f/2.8L IS USM + Extender RF 2x/ FL: 800mm/ Aperture-priority AE (f/5.6, 1/800 sec, EV -0.3)/ ISO 800/ WB: Daylight

EOS R5/ RF600mm f/4L IS USM/ FL: 600mm/ Manual exposure (f/10, 1/160 sec)/ ISO 100/ WB: Auto

EOS R5/ RF600mm f/4L IS USM+ Extender RF 2x/ FL: 1200mm/ Aperture-priority AE (f/8, 1/1250 sec, EV -0.3)/ ISO 2500/ WB: Daylight

 

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