topic Re: Canon RF 2x work with EF-RF adaptor in Camera Accessories

Canon RF 2x work with EF-RF adaptor

PurpleAnts — Sun, 23 Jun 2024 18:04:49 GMT

Hi, I try to play some telegragh with a 70-210 ES lens on EOS R. I am currently using a EF-RF adaptor to mount the EF lens to EOS R. Can I add a RF 2x mount between the R5 and EF-RF adaptor and make the lens to 400mm? Thank you.

Re: Canon RF 2x work with EF-RF adaptor

p4pictures — Sun, 23 Jun 2024 18:15:25 GMT

Unfortunately this nice idea doesn’t work. Physically the inside dimensions of the EF to EOS R mount adapter do not allow the protruding front part of either the RF 2x or the RF 1.4x to fit inside. I have tried this myself last year so I know it to be true.

Re: Canon RF 2x work with EF-RF adaptor

ebiggs1 — Mon, 24 Jun 2024 15:10:45 GMT

"Can I add a RF 2x mount between the R5 and EF-RF adaptor ..."

Whether that will work or not I don't know since I have never tried it. However, if it doesn't fit you could try one of the off brand tel-cons from Kenko, Tamron or Sigma. Personally I am not a fan of any tel-con but that said I have about a dozen of them. I know, I know its just curiosity but it has confirmed my basic dislike for a tel-con.

There are a few, very few, lenses where the combo does work well together, IMHO. The ef 70-200mm f2.8 lens is one of them but with the 1.4x model and not the 2x. As a matter of fact I don't consider the 2x to be of any use on any lens. I have used the Sigma 1.4x on my Sigma 150-600mm S lens and it works fairly well as it does on my 120-300mm Sigma f2.8 lens.

The Kenko seems to be as good as an off brand generic tel-con can be. No where as good as the Canon model or even as good as Tamron or Sigma but it m ay do what you want.

Re: Canon RF 2x work with EF-RF adaptor

kvbarkley — Mon, 24 Jun 2024 15:30:00 GMT

Ken Rockwell did it with an R and EF100-400 with the 1.4 *and* 2.0 converter!

https://kenrockwell.com/canon/eos-r/r.htm

Re: Canon RF 2x work with EF-RF adaptor

p4pictures — Mon, 24 Jun 2024 15:55:15 GMT

I often use the EF 70-200mm f/2.8L IS II USM with an Extender EF 1.4x III on the EF to EOS R mount adapter with my EOS R cameras and also with the EF 100-400mm f/4.5-5.6L IS II USM.

When I had the 1.4x and 2x RF extenders last year I thought that mounting the EF EOS R adapter on them would allow the extender to be used with all kinds of EF lenses, but it was obvious that they physically don't fit.

Re: Canon RF 2x work with EF-RF adaptor

p4pictures — Mon, 24 Jun 2024 16:22:57 GMT

Just found these pictures I took from when I tried to make this work.

This is Extender RF 1.4x and the EF to EOS R control ring mount adapter, though it is also the same for the plain adapter without control ring.

Re: Canon RF 2x work with EF-RF adaptor

PurpleAnts — Wed, 26 Jun 2024 05:04:14 GMT

Thank you guys. Seems EF lens + EF extender + RF converter works while EF lens + RF coverter + RF extender doen't. I will pursue the fist path and give it a try.

Re: Canon RF 2x work with EF-RF adaptor

davelawrence — Sat, 17 Aug 2024 17:27:15 GMT

PurpleAnts,

I have a similar question. Did you find out if EF lens + EF extender + RF converter works works?

Re: Canon RF 2x work with EF-RF adaptor

p4pictures — Mon, 19 Aug 2024 17:29:22 GMT

You can mount the EF to EOS R mount adapter on an EOS R-series camera. Then you can put the EF extender on to the mount adapter and then fit a compatible EF lens on the EF extender.

I have done this many times with the EF EOS R mount adapter, EF Extender 1.4x III and EF 100-400mm f/4.5-5.6L IS II USM, EF 70-200mm f/2.8L IS II USM and EF 135mm f/2L USM lenses.

It is NOT possible to put an RF extender on the camera, then the the EF to EOS R mount adapter the front of the RF extender. The combination won't physically fit.

Re: Canon RF 2x work with EF-RF adaptor

davelawrence — Tue, 20 Aug 2024 01:07:38 GMT

Thank you!

Re: Canon RF 2x work with EF-RF adaptor

DJ_aa7 — Sat, 17 May 2025 15:23:44 GMT

This can only be done with a 3rd party adapter, not the canon ef-eos rf adapter. But it still doesn't fit those and people are filling/scraping/cutting the 3rd party adapters so the rf extender front element fits.

So you have to diy modify the adapter, making sure not to damage the electronics. The lens will focus, but slower. In Lightroom, it will show the rf extender was used, but the incorrect focal length (it will show the focal length of the lens by itself without the extender's multiple. But it's just exif data and doesn't affect the image.)

DO THIS AT YOUR OWN RISK AS YOU MAY DAMAGE YOUR RF EXTENDER, LENS, AND CAMERA AND IS NOT SUGGESTED BY CANON NOR 3RD PARTY MANUFACTURERS OF THEIR ADAPTERS!!!