Canon RF lens mount

The Canon RF lens mount is an interchangeable-lens mount developed by Canon for its full-frame mirrorless interchangeable-lens cameras, and featured first by the EOS R, followed by the EOS RP. The RF mount was announced in September 2018. In May 2022, Canon announced APS-C EOS R cameras (the EOS R10 and EOS R7) and RF-S lenses designed for these cameras.

The RF mount allows for the use of Canon EF and EF-S mount lenses using one of three Canon-made lens adapters. When an RF-S or EF-S lens is attached, however, the camera will only function as an APS-C camera, not a full-frame camera.

Details
Canon full-frame cameras have used the EF lens mount since 1987. In comparison with that mount, the RF mount's inner diameter is the same at 54 mm. The RF mount's flange focal distance at 20 mm is much shorter than that of the Canon EF and EF-S mounts at 44 mm. The EF-M mount has a flange focal distance of 18 mm.

An EF-EOS R lens adapter enables Canon EF, EF-S, TS-E and MP-E lenses to be used on cameras that have the RF mount. The three adapters have differing features:
 * Mount Adapter EF-EOS R
 * Control Ring Mount Adapter EF-EOS R – the Mount Adapter EF-EOS R with a lens control ring
 * Drop-In Filter Mount Adapter EF-EOS R – the Mount Adapter EF-EOS R with the ability to use drop-in filters, either a variable neutral density (V-ND) filter or circular polarising (C-PL) filter, and a clear (CL) filter, released in 2019.

If an EF-EOS R Mount Adapter is used to mount an EF-S lens, the image will have to be cropped by 1.6x due to the smaller image circle on EF-S lenses.

Lenses
When Canon announced its first R-series body, it announced four new RF-mount lenses:
 * RF 24–105mm L IS USM
 * RF 28–70mm L USM
 * RF 50mm L USM
 * RF 35mm MACRO IS STM — 0.5× maximum magnification.

In conjunction with the February 2019 announcement of the entry-level full-frame EOS RP, Canon announced six additional lenses would be released by the end of that year, although it did not indicate release dates for any of them:
 * RF 85mm L USM
 * RF 85mm L USM DS — Same as the above, except includes "defocus smoothing" technology intended to improve bokeh. According to Canon, the effect is similar to that of an apodization filter, but achieved through special lens coatings instead of a filter.
 * RF 15–35mm L IS USM
 * RF 24–70mm L IS USM
 * RF 24–240mm IS USM
 * RF 70–200mm L IS USM

In 2020, Canon introduced seven new RF mount lenses:
 * RF 24–105mm IS STM
 * RF 600mm IS STM — fixed-aperture lens
 * RF 800mm IS STM — fixed-aperture lens
 * RF 85mm MACRO IS STM — 0.5× maximum magnification
 * RF 50mm STM
 * RF 70–200mm L IS USM
 * RF 100–500mm L IS USM

In 2021, Canon introduced seven new RF mount lenses:
 * RF 100mm L MACRO IS USM - 1.4× maximum magnification
 * RF 400mm L IS USM
 * RF 600mm L IS USM
 * RF 14–35mm L IS USM
 * RF 16mm STM
 * RF 100–400mm IS USM
 * RF 5.2mm L Dual Fisheye

In 2022, Canon introduced the first RF-S lenses (RF-S 18-150mm and the RF-S 18-45mm) for APS-C Sensors, together with the R7 and R10 camera bodies with the first built in APS-C Sensor in the R-System.

In 2022, Canon introduced seven new RF mount lenses:
 * RF 1200mm L IS USM
 * RF 800mm L IS USM
 * RF-S 18-150mm IS STM
 * RF-S 18–45mm IS STM
 * RF 24mm MACRO IS STM - 0.5×maximum magnification
 * RF 15–30mm IS STM
 * RF 135mm L IS USM

Canon has introduced eight new RF mount lenses:
 * RF 24–50mm IS STM
 * RF 28mm STM
 * RF-S 55–210mm IS STM
 * RF 100–300mm L IS USM
 * RF 10–20mm L IS STM
 * RF-S 10–18mm IS STM
 * RF 200–800mm IS USM
 * RF 24–105mm L IS USM Z

RF-mount lenses are not compatible with EF, EF-S or EF-M mount camera bodies. RF-S lenses can be used on full-frame RF cameras. However, the image will be cropped by 1.6×.

Compatibility
The cameras that can use the RF mount are:
 * Canon EOS R
 * Canon EOS RP
 * Canon EOS Ra
 * Canon EOS R1
 * Canon EOS R3
 * Canon EOS R5
 * Canon EOS R5 Mark II
 * Canon EOS R5 C
 * Canon EOS R6
 * Canon EOS R6 Mark II
 * Canon EOS R7
 * Canon EOS R8
 * Canon EOS R10
 * Canon EOS R50
 * Canon EOS R100
 * Canon EOS C70 Cinema Camera
 * RED Komodo 6K

3rd party RF-mount lenses
Note: The Samyang, Yongnuo, and Viltrox autofocus lenses are discontinued due to requests by Canon