A lens mount is the connection between lenses and camera bodies. Canon created the RF lens mount for their new mirrorless cameras which was announced in 2018. The RF lens mount was first featured in the EOS R and now appears in many Canon mirrorless cameras including the R5 and R7.
Additionally in 2022 Canon created RF-S lenses which are designed for cropped RF cameras. If a RF-S lens is attached to a full frame RF mount camera it’ll function as a can APS-C camera.
Canon’s older EF lens mount has been around since 1987. Both the Canon EF and RF mounts consist of a 54mm diameter but the RF mount is designed for a 20mm flange focal distance (the distance from the sensor to the lens). This allows Canon to create new form factors for lenses letting more light into the sensor.
Some of the more popular RF lenses include:
More RF lenses can be seen here.
Can you use RF lenses on EF mounts?
You cannot use RF lenses on an EF mount Canon camera. Since Canon RF lenses are designed for mirrorless cameras they are designed to be closer to the camera sensor. This makes it impossible to use on EF mount bodies since the EF mount bodies are larger with more space between the sensor and lens mount. Additionally an RF lens will not connect to a EF mount since the connection is different.
Can you use EF lenses on RF mounts?
While EF and EF-S lenses won’t work directly on the RF mount you can use them with RF camera. To use a EF lens on an RF mount camera you’ll have to get the official Canon EF to RF mount adapter which are typically around $100. From my usage the adapter works exactly like you’d expect and all of my EF lenses worked perfectly on my new Canon mirrorless cameras.
I hope this quick post gave you a better understand of what an RF lens is. If you have any questions about the Canon RF system let me know in the comments below!