One of the biggest questions photographers face when moving from DSLR to mirrorless is how well their existing lenses will perform—especially when it comes to Canon EF to RF Adapter Autofocus. While the transition might seem overwhelming at first, it often enhances lens performance and makes an immediate switch to RF lenses unnecessary.
Canon’s EF to RF adapters make the process smooth and reliable. In fact, autofocus performance often improves when EF lenses are paired with the advanced AF systems found in Canon’s mirrorless bodies. In my own experience adapting EF lenses to the Canon R5, the upgraded autofocus was one of the most surprising and impressive benefits.
This article answers common questions about using Canon EF lenses on RF-mount cameras, explores the available adapter options, and offers firsthand insights into the transition from DSLR to mirrorless—with a close look at Canon EF to RF Adapter Autofocus performance.
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Key Takeaways
- EF lenses work flawlessly on Canon RF-mount bodies using the official Canon adapter.
- Autofocus often improves, especially on newer mirrorless cameras like the Canon R5.
- Canon’s adapters preserve image quality and functionality—no glass is added unless you use drop-in filters.
- The control ring version of the adapter replicates RF lens functionality for added convenience.
- Third-party adapters can save money but may introduce minor issues like lens flare or reduced build quality.
- You can’t adapt RF lenses to EF cameras—the compatibility only works one way.
Canon EF-EOS R Adapters
Canon’s leap into the mirrorless scene has brought with it a nifty solution for those who’ve collected Canon EF glass over the years – the Canon EF to RF adapter. These adapters are lifesavers for those of us transitioning to the mirrorless system without wanting to abandon our collection of EF lenses.
The most basic, and budget-friendly, is the standard Canon EF to RF Adapter. It’s a no-frills option that does its job perfectly, maintaining the original quality of your lenses. I’ve found it works like a charm, providing a seamless link between my camera and lenses. Canon EF to RF Adapter Autofocus actually feels faster and more accurate than it ever did on my DSLR bodies, especially with eye detection turned on.
Stepping up, the Canon EF to RF Adapter with Control Ring is nice if you want a control ring like the new RF lenses offer. It replicates the programmable control ring feature found on RF lenses, letting you adjust settings like aperture or ISO right from the lens. Personally I find the controls on my R5 sufficient for quick adjustments, but people adapting to camera bodies without dedicated controls for shutter speed, iso and aperture might find this feature extremely helpful.
Lastly, there’s the Canon EF to RF Adapter with Drop-In Filter, a favorite among ND filter aficionados. It allows the use of a single set of ND filters across all your lenses, which is a fantastic cost saver and more convenient. The only downside to this adapter is the mandatory clear filter when you’re not looking to use the ND option, introducing an extra element that could affect image clarity.
Check Price: Canon EF-EOS R Adapters
3rd Party Canon EF-EOS R Adapters
Venturing beyond Canon’s official gear, many photographers, myself included, have explored third-party options for EF to RF adapters. Among these, Vello and Commlite are prominent names, but all 3rd party adapters come with their quirks.
Vello’s adapter caught my attention with its good autofocus performance and clarity. However, like most aftermarket adapters, it lacks the internal bellows found in Canon’s adapter, leading to halo effects when shooting in bright conditions. It’s a noticeable drawback for those of us keen on preserving the original quality of our EF lenses.
On the other hand, Commlite offers a tempting balance between cost and performance. Its autofocus and clarity are also great. But the build quality doesn’t quite match up to Canon’s adapter. Despite these drawbacks, aftermarket adapters usually work well enough to be an attractive choice for budget-conscious photographers or hobbyists.
Check Price: 3rd Party EF to RF Adapters
Pros and Cons of EF to RF Adapter
When I transitioned to a mirrorless system, the Canon EF to RF adapter autofocus became an essential part of my kit. I had built up a solid collection of EF lenses over the years, and I was genuinely concerned about whether they’d work well with my new camera. To my surprise, not only did they mount without issue, but they also performed better—especially when it came to autofocus—than they ever had on my older DSLRs.
The improved speed and accuracy were immediately noticeable, and I didn’t feel like I was compromising on image quality or functionality. While native RF lenses are still optimized for the mirrorless system and offer some clear advantages, being able to rely on my trusted EF glass made the transition far easier and more affordable.
That said, using an adapter isn’t without its limitations. Below, I’ve outlined the key pros and cons of using an EF to RF adapter with your Canon mirrorless camera.
Pros
- Expanded Lens Compatibility: The most significant advantage is the ability to use your existing collection of EF lenses with a new RF-mount camera system. This is particularly beneficial if you’ve already invested in high-quality EF lenses.
- Cost Savings: Instead of buying new RF lenses, which can be expensive, you can continue to use your EF lenses, saving money in the short term.
- Improved Autofocus: Good quality adapters will improve both the speed and accuracy of your old EF lenses by taking advantage of the new mirrorless camera’s autofocus system.
- Additional Features: Some adapters, like the Canon Control Ring Mount Adapter, add functionality, which is present on native RF lenses but not on EF lenses.
- Preservation of Image Quality: High-quality adapters do not introduce additional glass elements between the lens and the sensor, thus maintaining the original image quality of the lens.
Cons
- Potential for Reduced Performance: When compared to native RF lenses on mirrorless bodies, adapted EF glass will not perform as well.
- Extra Bulk and Weight: Using an adapter adds extra length and weight to your camera setup, which can make it slightly more cumbersome.
- Compatibility Issues: Not all EF lenses may be fully compatible with all functions of RF-mount cameras when using an adapter, potentially limiting certain features.
- Cost of Good Adapters: While cheaper than buying new lenses, high-quality adapters can still be a significant investment, and opting for less expensive, lower-quality adapters may introduce issues like poor fit or build quality.
- Potential for Flare: Some users have reported increased lens flare when using certain 3rd party adapters, due to less effective designs of the internal chamber.
Can You Use Canon EF Lens on RF Cameras?
Yes, you can use Canon EF lenses on RF-mount cameras by using the Canon Mount Adapter EF-EOS R. This adapter allows full compatibility between EF and EF-S lenses and Canon’s mirrorless EOS R system, preserving functionality and image quality. Many users, including myself, have found that pairing EF lenses with cameras like the Canon R5 actually enhances autofocus performance compared to older DSLRs such as the 5D Mark III, thanks to the advanced AF system in mirrorless bodies. Canon EF to RF Adapter Autofocus performance is one of the most notable benefits of this transition. However, it’s important to note that this is a one-way compatibility: RF lenses cannot be used on EF-mount DSLR cameras. So while adapting older EF lenses to RF cameras is easy and effective, you can’t do the reverse.
Do EF-RF Lens Adapters Affect Autofocus?
The Canon EF to RF adapter autofocus performs exceptionally well—if you’re adapting Canon EF lenses to RF-mount bodies. On my Canon R5, I found that my EF lenses actually focused faster and more accurately than they ever did on my DSLRs. Eye AF tracking was noticeably better, and overall performance felt like a significant upgrade.
However, this kind of seamless experience is only guaranteed with Canon glass. Many photographers have reported autofocus issues when adapting Sigma or Tamron EF lenses, even when using Canon’s official adapter. So while Canon EF lenses adapt beautifully to mirrorless bodies, third-party results can be hit or miss.
Does The Canon EF to RF Adapter Reduce Quality?
No, the official Canon EF to RF adapter does not reduce image quality. Both the standard version and the control ring variant contain no internal optical elements—they simply maintain the proper flange distance between the EF lens and the RF sensor. As a result, light passes through cleanly, preserving the full optical performance of your Canon EF lenses on RF-mount cameras.
However, there are some important caveats. When using the Canon EF to RF adapter with drop-in ND or variable filters, an additional glass element is introduced into the light path. Depending on the quality of the filter, this can cause minor image degradation or aberrations, which is a normal trade-off with any added optical component.
Additionally, third-party EF to RF adapters may reduce image quality. Some users have reported issues like halo effects, which can be caused by the lack of internal bellowing or proper internal light control. For the most consistent and reliable performance, the official Canon adapter is strongly recommended.
You neglected to mention that when using EF-S lenses on an R5 you only get 17.5 megapixels not 45. EF remains 45 megapixels
A good point worth mentioning! Yes, the image projected by an EF-S lens is designed for an APS-C sensor size, meaning it won’t cover the entire area of a full-frame sensor. This will result in reduced resolution when you adapt them to a full frame body as you describe.
I don’t recognize what you tell about the ef-rf adapter. I have a focussingproblem with my canon r6 mkII in combination with a sigma 150-600. For my type of photography (birds) is it frustrating that I sometimes have to wait more than 5 seconds before the subject is in focus. (The combination with my older 5d mkIII was perfect.)
Aww man I could see that being super frustrating! I’m using EF Canon glass and it’s a flat out better experience then it was with my older dslr bodies. The adapter must not like your Sigma glass. Bummer :-/
You are claiming that there is “Potential for Reduced Performance” when an EF lens with an EF-RF adapter is compared with the same RF mount lens.
Even though RF mount lenses are newer lenses, possibly with optically better quality glass as well as better design for optics, has it been proven scientifically and DEFINITIVELY that EACH RF lens produces better quality photographs than the corresponding older EF lenses of the same kind???
Keep in mind that RF lenses are far more expensive than EF lenses.
I’ve also read that the build quality of some RF lenses is not as good as corresponding EF lenses.
BTW, it feels, subjectively of course, that my older 5D Mk II build quality is better than the R and the R5 that I have.
You make some good points about the durability of the old ef lenses vs the new R mount. I personally still use all of my old EF glass so I don’t have first hand experience with the durability of the R mount lenses. I’ll defer to others that have owned them and beat on them as to their durability.
That said, this post is centered around the comparison of the autofocus performance between EF Lenses vs R lenses when adapted to mirrorless bodies. In this respect the R lenses are “better” because they focus faster. Your point is a good one that EF lenses might be better in other respects like affordability and build quality, but in my testing, the R lenses have better autofocus performance compared to the EF lenses.
Does this mean the R lenses are better overall? No it doesn’t. I’m definitely not a newer is always better person. With all of the above said, I still use my EF lenses for my work, because 1) I already had them and 2) they perform significantly better then they did on my old 5DMK III and 3) the image quality is still excellent. Is the image quality better on some of the new R lenses, certainly. Is it enough of a earth shattering difference to replace all of my old EF L glass? Certainly not IMHO.
Whilst I am using the R6 MkII with the genuine Canon RF-EF adapter I find auto focus very much better than with my old 5D Mk II body. However, I understand that I do not benefit from the R6 MkII body image stabilisation whilst using the adapter. Would you know if this is correct? I have been informed that one needs RF lens for complete stabilisation.
You do get stabilization with EF lenses on the R6 MkII—even with the adapter—but the maximum effectiveness is reserved for RF lenses, especially those with built-in IS.
If your EF lens has built-in IS, the camera combines it with IBIS for up to about 5 stops of stabilization.
RF lenses with built-in IS offer up to 8 stops of coordinated stabilization, since they’re fully optimized for the system.
Thank you for your prompt and informative reply. I had been considering the RF 100-500 in place of my EF 100-400 but I will now retain this, especially as I have the 1.4x and 2x EF extenders. Many thanks
No problem! The only downside of this that I’ve come across is that Canon will no longer service my old EF lenses. You can find third party people who will do it online, but that can be hit or miss in my experience compared to Canon’s service center.