topic Re: Differences between EF-RF adapters by Canon, K&F, and Meike in Gear Guide

Differences between EF-RF adapters by Canon, K&F, and Meike

ochia03 — Tue, 30 Dec 2025 13:24:56 GMT

I am looking at getting an EF-RF adapter for my new R50. What is the difference between the 179CAD Canon adapter, or the 64 CAD K&F concept adapter or the 72CAD Meike adapter? Is there any reason I should spend so much more on the canon first party verion?

Re: EF-RF adapter question

Waddizzle — Tue, 30 Dec 2025 11:08:29 GMT

When Canon first introduced the R Seties oof cameras, the market was flooded with third party mount adapters. Almost none of them worked properly.

Problems ranged from error codes to batteries being drained overnight to damaged cameras.

Re: Differences between EF-RF adapters by Canon, K&F, and Meike

March411 — Tue, 30 Dec 2025 14:11:42 GMT

When I transitioned from DSLR to Mirrorless I owned a fairly decent stable of EF lenses. My thought was to purchase the body and then slowly replace my EF lenses.

I purchased the Meike adapter thinking that it was a simple pass through from the lens to the body, not so simple. The Meike when used with some EF lens would rack and had challenges locking focus. I still owned my 90D and my 5d Mk IV so it wasn't a huge issue so I decided to test adapters.

I test the adapters you mentioned as well as Vello, Commlite and both of the Canon adapters. The third party adapters were inconsistent and rarely worked 100%. Focus racking, metadata missing, poor or no ability to use burst shooting, rapid battery drain and error 70 messages occurred with third party while the Canon adapters were simply an extension to the lens, zero issues.

RF lenses have a 12-pin connection to the camera, while EF lenses have 8 pins. This allows RF lenses to communicate with the camera faster and more efficiently. My thoughts on the adapters it this: while using an EF lens on an EOS R system camera and a third party adapter you may experience limitations because third parties have not perfected the communication protocols of the lens, adapter and body.

It's just my opinion but it's worth the additional expense to have consistent a reliable performance. I only use Canon at this point. I hate equipment failures when I am shooting.

Re: Differences between EF-RF adapters by Canon, K&F, and Meike

deebatman316 — Tue, 30 Dec 2025 14:28:22 GMT

Another thing to note is that EF-RF Mount adapters are not changing RF Mount communication to EF Mount communication. The camera detects what lens is mounted and switches communication protocols based on the lens mounted. All the EF-RF Mount adapter is just an extension tube that puts the EF lens at the correct distance away from the image sensor.

Re: Differences between EF-RF adapters by Canon, K&F, and Meike

ebiggs1 — Tue, 30 Dec 2025 16:18:04 GMT

Always, always stick with Canon brand gear for Canon gear unless you have and there is a good reason not to.

Re: Differences between EF-RF adapters by Canon, K&F, and Meike

jrhoffman75 — Tue, 30 Dec 2025 17:47:12 GMT

@deebatman316 wrote:

Another thing to note is that EF-RF Mount adapters are not changing RF Mount communication to EF Mount communication. The camera detects what lens is mounted and switches communication protocols based on the lens mounted. All the EF-RF Mount adapter is just an extension tube that puts the EF lens at the correct distance away from the image sensor.

Despite this, discussions here, on FB and other forums report problems with third party adapters that go away when the Canon brand product is used.

Re: Differences between EF-RF adapters by Canon, K&F, and Meike

deebatman316 — Tue, 30 Dec 2025 17:50:12 GMT

My response was to Marc. But I always recommend using the Canon brand adapter. 3rd Party adapters cause all sorts of problems.

Re: Differences between EF-RF adapters by Canon, K&F, and Meike

March411 — Tue, 30 Dec 2025 19:00:01 GMT

ebiggs nailed it for this specific item, I say that because both of us have used third party lenses when we couldn't find what we needed from Canon.

The bottom line....

Authentic Canon adapters communicate with the same language and logic of other Canon camera components/products ensuring 100% functionality. This results in improved overall performance as it pertains to AF, and automatic functions within the R systems advanced features. There is no programming logic in the sense of altering the lenses performance or enhancing or adding additional features it merely guarantees the electronic signals are transmitted correctly.

The basic Canon Mount Adapter EF-EOS R is primarily a mechanical spacer that maintains the correct flange distance, the distance from the lens mount to the sensor. However, it is not a dumb adapter as it contains electronic contacts to facilitate communication between the EF or EF-S lens and the R systems camera body permitting autofocus, IS and aperture control to function properly.

Some will say that third party adapters perform as well as the Canon adapter. Others state that they have experience with the lenses racking and not locking focus quickly, the loss of certain functionalities such as auto-focus or auto-exposure. Personally, I have experienced challenges with third party and my thought process is this…..

Why spend a significant amount of money on camera assets and skimp on a piece of hardware that functions as a communication gateway between your lens and camera body. Peace of mind and consistent performance in the field are worth the small added expense to purchase authentic Canon adapters that result in not having challenges with my gear.

Re: Differences between EF-RF adapters by Canon, K&F, and Meike

ebiggs1 — Wed, 31 Dec 2025 16:40:28 GMT

“… it is not a dumb adapter as it contains electronic contacts to facilitate communication between the EF or EF-S lens and the R systems camera body permitting autofocus, IS and aperture control to function properly.”

A valid point.

Going from 8 contacts to 12 indicates there more than a simple ‘spacer’ involved.

”Why spend a significant amount of money on camera assets and skimp on a piece of hardware that functions as a communication gateway between your lens and camera body.”

I have never understood that either.

Re: Differences between EF-RF adapters by Canon, K&F, and Meike

mleclerc7 — Tue, 03 Mar 2026 18:28:46 GMT

On the same topic of adapter functionality: I use the RP body (RF) with a Tamron 18-270 (EF) via a 3rd party adapter. I have to set the crop ratio manually in Av, Tv and C modes , but affecting the ratio is not possible in the automated and scenic modes. I understand from reading this thread that some meta info is handled by the adapter.

Is it possible that using the Canon adapter would make the RP body properly recognize the Tamron EF lens and set the crop ratio properly across all the camera modes ? Anybody with relevant experience ?

Re: Differences between EF-RF adapters by Canon, K&F, and Meike

deebatman316 — Tue, 03 Mar 2026 18:41:15 GMT

No because the lens tells the camera that it’s designed for APS-C.

Re: Differences between EF-RF adapters by Canon, K&F, and Meike

March411 — Tue, 03 Mar 2026 19:09:50 GMT

Hey @mleclerc7 ,

I run several adapted lenses on my R bodies and the meta data is accurate. Surprisingly my latest purchase the Laowa 100mm macro is even picked up correctly and displays in Canon DPP with no issues. I use only Canon adapters, tested others and the results were poor.

Re: Differences between EF-RF adapters by Canon, K&F, and Meike

mleclerc7 — Sat, 07 Mar 2026 22:02:24 GMT

I just received the Canon-brand adapter and sadly the issue persists.

In Av Mode I have the option to set Cropping/aspect Ration to 1.6, to match my Tamron zoom. (Panel 1-1 on the menu, second item from the top)

In Scene or A+ modes, I do not have that option, and the image is not cropped. The Tamron Lens is EF (Model B003) and the RP switches to the proper crop ratio when I use the Canon 50mm 1.4 EF lens.

Am I missing something ? Is my Tamron just too old ?

Any insight appreciated !

Image not cropped in A+ mode using the Tamron EF zoom

Re: Differences between EF-RF adapters by Canon, K&F, and Meike

jrhoffman75 — Sat, 07 Mar 2026 22:06:30 GMT

I suspect the problem is that it is a third party lens. In the “ beginner “ modes many options are disabled.

Re: Differences between EF-RF adapters by Canon, K&F, and Meike

March411 — Sat, 07 Mar 2026 22:26:06 GMT

Hey @mleclerc7 exactly which lens is giving you challenges, please give the full name.

Have you checked to see if the firmware can be updated or is it to old?

Re: Differences between EF-RF adapters by Canon, K&F, and Meike

mleclerc7 — Sat, 07 Mar 2026 22:33:26 GMT

Hi John. The lens name is Tamron AF18-270mm F/3.5-6.3 Di II VC LD Aspherical [IF] MACRO. It is a discontinued model from 2011. The model number is B003E. Here the link the the amazon description. (not where I bought it. Just for the details provided): Tamron AF 18-270mm f/3.5-6.3 Di II VC LD Aspherical IF Macro Zoom Lens for Canon Digital SLR Cameras (Model B003E) : Amazon.ca: Electronics

Re: Differences between EF-RF adapters by Canon, K&F, and Meike

jrhoffman75 — Sat, 07 Mar 2026 22:43:43 GMT

Only Canon lenses use the EF-S mount. Third party lenses, even though they may only be "sized" for APS-C, use the EF mount.

It is the EF-S mount on the adapter that triggers the crop mode. It needs to be manually set for third-party EF APS-C design lenses. The A+ mode doesn't allow access to many menu options, like the selection of the crop mode.

Creative Mode menu:

Basic mode menu

Re: Differences between EF-RF adapters by Canon, K&F, and Meike

mleclerc7 — Sun, 08 Mar 2026 13:31:35 GMT

Thank you for the clear and complete answer. Now I know where I stand.

Re: Differences between EF-RF adapters by Canon, K&F, and Meike

ebiggs1 — Sun, 08 Mar 2026 16:59:29 GMT

WOW! A 15:1 zoom ratio. I was not even a lens.