Canon has extended its lens lineup for its full-frame mirrorless EOS R cameras, with the launch of the RF 50mm F1.8 STM and the RF 70-200mm F4L IS USM. The former employs a new optical design compared to its EF-mount predecessors, while the latter exploits a similar extending zoom mechanism to its f/2.8 RF sibling, enabling a particularly compact size.

Canon’s RF 50mm F1.8 STM uses a new optical design with an aspherical element

Turning our attention first to the 50mm f/1.8, Canon says that it’s been designed to deliver high image quality in a small and lightweight design. To this end, it employs a precision molded optic (PMO) aspherical element in its 6 element, 5-group design, which should improve off-centre sharpness at large apertures. The lens has both a metal mount and an electronic manual-focus ring that can be also be used to change exposure settings via a switch on the barrel. A stepper motor is used for quiet focusing down to 30cm, which provides 0.25x magnification.

Meanwhile, the 70-200mm f/4 is designed to deliver professional-level image quality in a super-compact design. Indeed at 83.5mm in diameter, 119mm in length and just 695g, it’s dramatically smaller and lighter than similar lenses. A dual Nano USM system is used for autofocus, with a minimum focus distance of 60cm and 0.28x maximum magnification. The 77mm filter thread is shared with the firm’s RF 24-105mm F4L IS USM.

Like it’s f/2.8 sibling, the RF 70-200mm F4L IS USM employs an extending zoom mechanism

As usual for Canon’s L-series optics, the lens is dust- and moisture-resistant, with a fluorine coating on the front element to repel oil and water drops. It also boasts a customisable, click-stopped control ring at the front for changing settings. Its three-mode optical stabilisation is rated to 5 stops on its own, or 7.5 stops benefit when used in concert with the in-body stabilisation on the EOS R5 and R6.

Both lenses should be available at the start of December, with the RF 50mm F1.8 set to cost £220 and the RF 70-200mm F4L IS USM, £1,700.