Extending the range of compatible lenses while maintaining their original field of view, the Canon EF-EOS R Mount Adapter 0.71xpermits attaching EF-mount lenses to RF-mount cine and mirrorless cameras. Intended for cameras featuring a Super 35 sensor size, this adapter also incorporates an optical system to increase the effective angle of view by 0.71x, reducing the effects of a full-frame to Super 35 crop factor and increasing the maximum aperture performance by one stop. Electric contacts are also incorporated into the adapter's design and maintain full communication between the camera and lens, as well as support metadata transmission and use of Dual Pixel AF with select Canon EF lenses. Also, the adapter has been specifically designed for the EOS C70 cinema camera and features four screws and a split locking collar to ensure a secure attachment.

Canon EF Lens to Canon RF-Mount Body    Designed for EOS C70 Cinema Camera    Adapt Full-Frame Lens to Super 35 Body    Increases Angle of View by 0.71x    Increases Maximum Aperture by 1 Stop    Electric Contacts Support DPAF and Data    Includes Secure-Attachment Mount

This adapter physically supports working with any Canon EF-mount lens; however, select lenses can maintain full Dual Pixel autofocus support and metadata transmission between the lens and camera, including:

• EF 16-35mm f/2.8L III USM
• EF 24-70mm f/2.8L II USM
• EF 24-105mm f/4L IS II USM

Related Questions and Answers

Q: 1. Can I use this mount adapter with an EF teleconverter and EF lens?

A: As long as the Canon EF Extender you use is compatible for use with the Canon EF lens you own, yes, you may use your Canon EF mount lens and Canon EF extenders like the Extender EF 1.4x III on the Canon Mount Adapter EF-EOS R.

Q: 2. By adding adapter, will you lose an f stop in the process?

A: Short answer: f is not affected. The "original" (unadapted EF lens on a DSLR camera) focal length and opening of the lens are not changed. Long answer: The new RF lens mount has a shorter flange focal distance (distance between rear objective lens and camera sensor) of 20mm compared to the flange focal distance on the EF mount (44mm). The mount adapter is simply a metal tube or spacer that restores the 44mm flange focal distance, so that the EF lens can be used on the RF body.

Q: 3. Is it possible to use a Canon EF teleconverter between this adapter and a lens such as the Canon 100-400 zoom?

A: Yes, you will be able to use the EF teleconverters with this adapter.

Q: 4. I inherited an old Canon T50 (1982) with 3 FD lenses. Will this adapter allow me to use these lenses with my SL1?

A: The Canon Mount Adapter EF-EOS R would not work. You would need an adapter that is FD lens to EF mount camera like this one. https://www.bhphotovideo.com/c/product/742933-REG

Q: 5. Will a Canon E mount lens work with this?

A: This adapter will only work with Canon EF-Mount lenses.

Q: 6. For anyone who has purchased this. Do you regret not purchasing the one with the control ring?

A: The most typical usage for the version with the control ring is to use it to adjust ISO. As such, if you are not needing a ring for that then you are unlikely to regret getting the Canon Mount Adapter EF-EOS R (B&H# CAMAEFRF) instead of the Canon Control Ring Mount Adapter EF-EOS R (B&H# CAMAEFRFCR).

Q: 7. This adapter is compatible with Canon EF lens, what about USM macro lenses?

A: EF/EF-S and USM are part of the same "system" but mean completely different things. EF/EF-S pertains to the mount (which is principally the requirement for the lens to work with this adapter), while the other pertains the type of autofocus motor (and has nothing to do with mounting the lens to a camera). To answer the question though, all of the EF/EF-S macro lenses with USM work with this adapter.

Q: 8. Does it works on a 6D mark II?

A: No, the Canon Mount Adapter EF-EOS R, B&H # CAMAEFRF, is not compatible for use with the Canon EOS 6D Mark II DSLR camera. The Canon EOS 6D Mark II DSLR camera is, by design, already compatible for use with EF lenses, and no lens adapter is required to connect an EF lens onto the Canon EOS 6D Mark II DSLR camera. The Canon Mount Adapter EF-EOS R is designed to connect EF-mount lenses onto the RF-mount lens mount used on Canon's mirrorless digital cameras, such as the Canon EOS R Mirrorless Digital Camera and the Canon EOS RP Mirrorless Digital Camera.

Q: 9. Is this what I need for Mark IV lenses to work on the RF 6?

A: Yes. This Canon EF-EOS RF adapter will allow you to mount your Canon DSLR lenses onto your Canon EOS R6 mirrorless camera body.

Q: 10. I got 18-135 Is usm (old one) so will it work with Canon Mount Adapter EF-EOS R?

A: The Canon EF-S 18-135mm f/3.5-5.6 IS USM Lens is compatible with the Canon Mount Adapter EF-EOS R.