topic Re: RF Lens on an EF camera body in EF & RF Lenses

RF Lens on an EF camera body

CuriousPR — Thu, 10 Aug 2023 01:10:01 GMT

Hello, everyone.

I understand that the newer mirrorless R/RF cameras can be fitted with an adapter that would allow them to use older DSLR lenses. I recently found out, however, that DSLR camera bodies could use R/RF lenses if the DSLR camera is fitted with the proper DSLR-body-to-R/RF-lens adapter.

The issue is that there seems to be a pretty conspicuous lack of information out there about obtaining an adapter allowing R/RF lenses on EOF bodies.

Although I can easily find places online where I can obtain an adapter that fits on a mirrorless R/RF camera allowing it to use older EOS lenses, I’ve been unable to find ANY sources where I can obtain an adapter that would fit on my EOS camera body - in my case a Canon T4i - which would allow it to accept R/RF lenses.

Does anyone know of any places or sources that have or talk about an adapter that can fit on an EOS camera body and which would allow that EOS camera to use R/RF lenses?

Thanks very much in advance. 🙂

Re: RF Lens on an EF camera body

rs-eos — Thu, 10 Aug 2023 01:24:38 GMT

That information you have found is false. You cannot use RF lenses on EF or EF-S Mount cameras. Look up flange distance for details.

Re: RF Lens on an EF camera body

CuriousPR — Tue, 27 Aug 2024 15:28:43 GMT

Thank you for that information, sir. I was reading last night with regard to the subject of flange distances and how (excuse my layman’s grasp) the distance on EOS cameras is quite deep compared to mirrorless cameras.

So there is no adapter that can be put on an EOS camera would allow it to fit RF lenses?

Re: RF Lens on an EF camera body

Tronhard — Thu, 10 Aug 2023 02:21:39 GMT

Absolutely, there is no adapter to put RF lenses on EF bodies. Simply put, RF lenses are designed to attach to bodies that have no mirror mechanism. Putting them a DSRL, which has to accommodate the mirror mechanism that has to have room to flip up between the sensor and lens rear element, is physically impossible. There may be claims about that there are, but the physics simply do not allow that.

Re: RF Lens on an EF camera body

CuriousPR — Thu, 10 Aug 2023 02:33:06 GMT

Thank you very much for this thorough explanation. Much appreciated, sir. 🙂

Re: RF Lens on an EF camera body

stormy — Mon, 26 Aug 2024 07:58:22 GMT

Seems folks continue to confuse others?

https://www.kentfaith.co.uk/blog/article_can-i-use-ef-m-lens-on-ef-mount_4741

major filter vendor has this text: "

No, you cannot use EF-M lenses on EF mount cameras without an adapter. EF-M lenses are designed specifically for Canon's mirrorless cameras with an EF-M mount, while EF mount lenses are designed for Canon's DSLR cameras with an EF mount.

However, with the use of an adapter, you can use EF-M lenses on EF mount cameras. Canon offers the EF-EOS M adapter, which allows you to use EF and EF-S lenses on EF-M mount cameras, as well as the EF-M lens adapter, which allows you to use EF-M lenses on EF mount cameras."

claiming both directions are possible, this is probably AI-text meets reality, or.. are WE in the dark and "it" knows better?

Re: RF Lens on an EF camera body

Tronhard — Mon, 26 Aug 2024 09:32:37 GMT

If one actually looks at the physics of the lenses and bodies, as well as the number and location of contacts, it should be clear that while EF and EF-S lenses can be adapted to the smaller EF-M mount, it does not work the other way around. People may claim that, but it does not make it so. Just because it's on the web doesn't mean you can trust it. Applying some common sense with an examination of the dimensions involved and basic physics will usually show the lack of veracity to those claims.

So, let's say this once and for all:
EF and EF-S lenses can be used on EF-M mount cameras (now no longer sold) via an EF to EF-M adapter
EF and EF-S lenses can be used on RF mount bodies via and EF-RF adapter, with some limitations. While EF-S could not be connected to FF DSLRs, (they fouled on the mirror) they can now physically fit a FF R-series camera body, because there is no mirror to get in the way, however because the cone and depth of projection of an image from EF-S lenses is specific to crop sensor bodies, where the distance to the sensor is closer, mounting one on a FF MILC camera will cause it to automatically move into crop sensor mode, reducing the recorded area by a factor of 2.56. This is clearly stated in the material in the Advanced User guides for each FF body.

EF-M mount lenses do not physically fit on Canon DSLRs or R-series MILC either natively or via adapters.

Re: RF Lens on an EF camera body

stormy — Tue, 27 Aug 2024 09:24:47 GMT

Right, getting harder to sift between right/wrong as more ai-generated content is produced... just wanted to quote real world example, from reputable "authority" that cause such discussions and debates on feasibility.. interestingly, they immediately removed the blog after sent an inquiry and replied, that adapter is no longer available 🙂 🙂 🙂 another standard reply 🙂

Thanks for clarifications...

Re: RF Lens on an EF camera body

Waddizzle — Tue, 27 Aug 2024 10:02:17 GMT

“ However, with the use of an adapter, you can use EF-M lenses on EF mount cameras. Canon offers the EF-EOS M adapter, which allows you to use EF and EF-S lenses on EF-M mount cameras, “

This claim is obviously incorrect.

Re: RF Lens on an EF camera body

ebiggs1 — Tue, 27 Aug 2024 14:46:36 GMT

"People may claim that, but it does not make it so. Just because it's on the web doesn't mean you can trust it."

However, there are about a half dozen guys on this forum that do know their stuff and you can take their info right to the bank as gospel. 😁 Perhaps I don't agree wit them 100% of the time but on this information they are 100% correct.

Re: RF Lens on an EF camera body

bp-foto — Tue, 03 Mar 2026 20:21:24 GMT

Someone odd to make one anyway. I know that you will not be able to use an rf lens on an ef body in a normal way, but in case that want to play with extention tubes for macro phortography it could be usefull to be able to mount en EF adapotor on an RF body and then convert it back again to an RF mount.

Re: RF Lens on an EF camera body

ebiggs1 — Wed, 04 Mar 2026 15:10:05 GMT

You are barking on a 3 year old thread. I doubt anyone carss any longer.

Re: RF Lens on an EF camera body

bp-foto — Wed, 04 Mar 2026 22:31:32 GMT

You disproof your own point by making that reply.
I came to this site via a google search yeasterday. Its no less relavant now.

Re: RF Lens on an EF camera body

rs-eos — Wed, 04 Mar 2026 22:33:57 GMT

Please read to solution to this thread. You said "Someone odd[sic] to make one anyway". It's not possible.

Re: RF Lens on an EF camera body

bp-foto — Wed, 04 Mar 2026 22:38:28 GMT

Ofcause it is, but it will only wotk for macro. It will just be an extention tube where you can use a product like the Meike MK-C-UP, witch dont exist for the rf mount.

Re: RF Lens on an EF camera body

bp-foto — Wed, 04 Mar 2026 23:50:05 GMT

it's super niche, and noone will realistically make it, but it could have a use case for something like this https://www.youtube.com/watch?v=PW-44IKD8l0

Re: RF Lens on an EF camera body

kvbarkley — Thu, 05 Mar 2026 00:57:57 GMT

We can’t help much we are just users. Go to the canon USA homepage and find the(+)feedback button. Of course if you want someone other than canon to make it, I have no idea who to contact.

Re: RF Lens on an EF camera body

bp-foto — Thu, 05 Mar 2026 02:03:28 GMT

It's not realy my post. I was just brain storming yesterday. I look at the setup in the youtube video and I would prefer to invest in a pancake lens for the RF mount if I want it to double as a macro lens. I guess the only realistic solution is that someone makes a product with the same functionallity as Meike MK-C-UP, but for the rf mount, and then I just have to pay 2-3 times the price for all the RF parts I'm forced to buy to have a setup simular to what is shown in the video, but with an rf lens as the primary component.

Re: RF Lens on an EF camera body

ebiggs1 — Thu, 05 Mar 2026 15:36:10 GMT

"You disproof your own point by making that reply."

Not really. I get notices when someone responds to any thread but as you see until you there wasn't a reply for three years. It's done it was answered.