RF Lens on an EF camera body

[CuriousPR]

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.  🙂

[rs-eos · Accepted solution]

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. 

[rs-eos · Accepted solution]

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. 

[CuriousPR]

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?

[Tronhard · Accepted solution]

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.

[CuriousPR]

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

[stormy]

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?

[Tronhard]

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.

[Waddizzle]

“ 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. 

[stormy]

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...

[ebiggs1]

"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.