How Well Does the Canon R5 Work With EF Lenses?

With many photographers making the switch from DSLR to mirrorless systems, there are a lot of us wondering if all those old lenses we've acquired over the years will still work as well on new cameras, or whether we'll have to swallow the expense of all new lenses too.

There's been a lot of discussions recently on when to upgrade, whether to upgrade, or whether mirrorless technology is mature enough for working professionals yet. There's no denying that photographic technology has improved a great deal in the past few years. While not without teething problems, mirrorless systems from all major camera brands are becoming a tempting replacement for our DSLR cameras. Sadly, with new cameras come new lens systems. It isn't as simple as trading in your old camera for a new one and continuing to use all your existing lenses, or is it?

I was always advised to spend money on decent glass; it's a good investment, I was told. With a decent collection of L Series lenses in my kit bag, it's safe to say I'm quite heavily invested in the Canon system. Some of these lenses have been with me through three camera body upgrades. Now, I'm seriously considering switching to the Canon R5 as my main camera, and I'm concerned about how well the EF lenses will work with an adapter or whether I'll need to trade them in to replace them with RF lenses. This issue has led me to research a lot of articles and videos on the subject.

This video from Park Cameras looks specifically at the Canon R5 with the Canon EF 100-400mm L series lens. Any Canon shooters looking at moving from DSLR to mirrorless will be pleased to hear that claim that EF lenses work flawlessly with the new cameras when using a Canon lens adapter. Canon appears to have taken existing Canon users into consideration, as they have released three different EF adapters for the new RF system, one plain adapter, one with the addition of the multifunction control ring, and even one with a built-in variable ND filter, which will certainly please videographers.

What's the Catch?

From the research and real-world tests I've looked at, there's no serious catch to speak of, but there are significant advantages to using native RF lenses. Ben Harvey recently discussed his views on using the Canon R5 with adapted EF lenses; interestingly, he pointed out that the autofocus speed and accuracy using EF lenses were better than the performance of the same lenses on his Canon 5D Mark IV, although still not as fast as using native RF lenses. Still, any improvement is an improvement, in my opinion. Then, there are the negatives, the most obvious of which would be the additional size and weight from using an adapter on the front of the camera. The RF lenses also tend to be smaller than their EF counterparts, so there's further size and weight savings to be made by using RF lenses. Finally, an issue that I hadn't been aware of before researching this article is Canon's claim that burst shooting on the Canon R5, when using adapted EF lenses, is as slow as 6 fps, whereas it's claimed to be 12 fps using RF lenses. Real-world reviews seem to be getting 7-9 fps in burst mode when using EF lenses with the mechanical shutter. This might not be a deal-breaker for many people, but it's certainly worth considering. Also worth considering are the higher price of RF lenses when compared to their EF counterparts.

The good news is that if you're planning to keep a DSLR as a backup camera or you simply can't justify upgrading all of your lenses straight away, the new Canon mirrorless cameras will work incredibly well with your existing EF lenses. If you can put up with the size, weight, and slower burst, you'll save yourself a few thousand dollars by using your existing lenses. You'll probably still desire a full set of new RF lenses, though.

Are you considering switching from a DSLR to mirrorless? Would you use your old lenses or upgrade all your kit?
Have you recently switched to mirrorless, and have you had a good experience with adapted lenses? Let me know in the comments.

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Brad Wendes's picture

Brad Wendes is a British photographer and travel lover.
He began photographing parkour and acrobatics in 2010 and has since taken to portraiture and fitness photography.
Brad is a self-confessed geek, Star Wars fan, tech enthusiast, cat lover and recently converted Apple Fanboy.

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I have several cameras, bmpcc 4k, canon eos R, canon m6mk2. With adapters/speed boosters I can use my nice collection of EF lenses on all of them. This is such a big advantage, I don't even consider RF lenses in the near future. Incompatibility makes the RF lenses looking terribly expensive. Instead I started investing in FD lenses, which can also be adapted to anything.

I went from a 5d3 to an EosR just over 2 years ago. I got the control ring adaptor and it gives me the same functionality on my EF lenses as it does with the native RF lenses with the built in control ring. I don’t own any RF lenses and for what I shoot I cannot justify replacing my EF glass. Personally I’ve not had one issue with my adapted lenses, and, to me, I think the EF glass performs better on the R than on the 5d3.
I’ve also got an M6ii and along with my EF-m lenses I use the EF lenses adapted to it as well, something I couldn’t do if I had RF’s.
I think people get a little caught up in all the hype and forget how good the EF L lenses are and I doubt that most people could tell the difference once an image is printed.

You’re right, a lot of EF lenses are absolutely superb. And we can now pick them up at a much lower price than ever before!

I have gone from my 5D MK the canon R 6 Kit bought from Park cameras ( great company )
I bought the basic canon ring adapter And I have to say that I have a vast assortment of Canon EF lenses purchased over the years,
At 72 years old I have not the time on my side to invest in RF Lenses so My conclusion is that my EF lenses all work extremely well with my new set up.
to say that I am pleased is an under staement The R6 is a fantastic camera's I mainly shoot wild life and panaramic as well as astro photography.
great camera no regrets changing Highly recomened
Great video review
Geoff garner.

I have yet to touch an R5, but tomorrow, Canon is making a stop in Winnipeg to give interested shooters a chance to work with an R5/6. They suggested bringing a lens or two that I'd like to try, so I'm taking my 70-200 f2.8 II which is my favorite lens. Probably not a good idea, though. It may tempt me to head to the camera shop. :-)

You're going to love it!

That's what I'm afraid of. :-) I just checked the weather forecast since it's an outdoor shoot....40% chance of rain. Fingers and toes crossed!

Let us know how you get on. Every day I get more tempted to jump on the R5

Will do. My son is a wedding/event photographer is also waiting for my report. He shoots with a pair of 5DIVs. He's not convinced that it would be enough of an upgrade and isn't enthralled with EVFs. I guess he figures if his Pop thinks it's a worthwhile upgrade and that it works as advertised with EF/L lenses, he might try one.

Seriously try out the R6 with an Rf 24-105. Have the kids run at you. You'll be absolutely amazed. It's great for weddings. Better than any DSLR by a long shot for weddings.

I'd like to. I guess it depends on how many people show up. When I signed up for this, they asked which camera I'd prefer, so I chose the R5. If there's a 6 available, I'll give it a go.

So? How did it go?

It went very well. See my replies below.

All I can say is WOW! The focus speed is amazing as is the accuracy. I didn't do a whole lot of playing around with the focus options, but just that little bit of tinkering and it was a joy. The shot I attached is heavily cropped which was done on purpose to see just how nice it is to have a pile of pixels.

But, it's not perfect. I'm still not enthused about the EVF. And, I would have to add the battery grip. I'm one of those that likes a hefty camera. My 5DIV is grip equipped and it is very comfortable to shoot, especially with heavier lenses. But the results are terrific. Nicely done, Canon!

Damn, that is so clean, especially for being heavily cropped.

It's a nice camera. Getting a distant shot and cropping it like this shot was one of my objectives. The other was to see how well it handled my lens. Pretty much passed with A grades. :-)

Fantastic shot, thank you for sharing your experience. I’m certainly convinced! Only the EVF that might take some getting used to

I switched for shooting with manual lenses (mostly), where the viewer magnification helps nailing the shot. My eyesight is too bad for DSLR focusing manually (the 6D took the manual focusing screen with contrast enhancement, the 6Dii had a brighter viewer, but no possibility for a focusing screen, it became nearly impossible for me with my "special" lenses). And, of course, I wanted to use my dad's old lenses and buy some by myself second hand.

Maybe, in a view years, I'm ready for AF lenses (I do own the 24-105/4 L and the 35/1.8, but they are for travelling).

I have the full ATX Pro Tokina 2.8 set of EF lenses NONE of which work on my R6. My Canon 80-200mm 2.8 doesn't work either. My Sigma 24mm 1.8 works beautifully. My Tamron 17-35 2.8-4 works beautifully. My EF 100-400L worked well but the RF 100-500L stomps it. My Canon EF 28-135 IS and EF-S 55-250 IS work well. My 100-300L 5.6 is just as horrible as it as always been if not worse. It just focuses twice as fast to deliver mediocre results sooner and sounds like it wants to blow up. All my EF 70/75-300 suck just as bad as they always have. Why they didn't just repurpose the EF-S 55-250 for EF use I'll never know. Probably just didn't want cheap competition for the EF L glass.

I went from the Canon 5DMkIII to the R5 a little under a year ago and I'm happy. I upgraded to RF glass on the lenses I used most: 15-35mm f/2.8, RF 50 f/1.2 and RF 70-200 f/2.8. The last two EF lenses (EF 85 f/1.4 and EF 100mm f/2.8 macro) I don't shoot with as often, I'll stick with.

I upgraded from the 5DMIV to the R5 last year with a couple of RF lenses; the RF 28-70 f/2.0 and the RF 70-200 f/2.8, both of which are fantastic. I also bought the Canon EF adapter with the drop in filters and shoot real estate video with an EF Sigma Art 14-24 f/2.8 and the system works flawlessly. The results look beautiful and I could not be happier.

This is great to know.
I love my 100-400mm L MII and will eventually migrate to the RF system.
Good to know that this lens will not need to be replaced.

I just bought a r6 and am blown away how well it works with EF mount lenses + adapter. Note Amateur photographer so I do this for fun. Pic is had held Tamron 150-600mm g2. I am having so much fun with fast frame rate. I sold all my old kit. But kept a 50mm prime and the 150-600.

Hand held and not an R5 but I believe similar compatibility issues

EF lenses still have value because of the adapter and make for great backups as if one of your workhorse RF lenses go out you can fall back on your EF version. As you know RF lenses are hard to come by because of the shortage. The only con about the EF lenses on a mirrorless body is the length added compared to the RF version for example 70-200mm. Other than that EF lenses works just fine on my R5 and R6.

I started a photography business 3 years ago with nothing but a Canon SL2! Sure other LA photogs laughed at me when I showed up at spotlight events. As I made money, I reinvested in quality glass, and quickly I sold photos to travel and architecture magazines, NatGeo, and landed a principal photography contract with a famous long-running reality tv show - point being, good glass and some skill, outweighs going broke buying the best rig just to fit in. A few weeks ago I jumped from the SL2 to the Canon R5. It's amazing, the AF is sick, and a lightning fast fps (I'm used to a burst of 3 frames before it had to buffer haha!). Anyway, a few days ago I went out to grab some shots of bighorn sheep in Nevada, and just for kicks, after I got the shots I needed, I tried several of the efs lenses in my bag. I was most impressed with the 75-300mm, which I had rarely been able to get a clean shot with before on the SL2. Here are sample shots I got with the 75-300, which most folks call a soft backup lens. I was about 15 meters away (50 feet), in bright sun. I wouldn't have even thought that lens could grab such clean shots! With the solo bighorn photos, I show the full-body shot frame as it was recorded, and then a photo where I cropped in on his face. So yes, the R5 does make great use of the lenses. True the adapter might slow the shutter speed down a bit, and you get a 1.6x crop (ef/efs --> rf), so you just have to be mindful of your shot... you know, fall back on those ol' photography skills!

Great shots, the R5 does seem to get the best out of those old lenses (not to detract from the photographer)

I have a significant investment in EF lenses. However, when I went to the R5 I know it was time to update all of my lenses to the RF series. Sure, it's not an easy jump not make since most photographers have more invested in their lenses than the body. However, if you are going to make the jump to mirrorless cameras, you must do so with the lenses. There's too much to gain from RF lenses. I even sold my EF 400 f/2.8 after taking a big gulp. However, I will probably replace it with the 100 - 500. There's only one lens I would find it extremely difficult to part with, and that's a cherished 35 - 350 telescoping lens that has traveled with me on backcountry hikes for years because of its versatility.

Of course, this is only my opinion, so do with it as you wish.

I have a Canon EF/RF adapter. I have found downsides.The biggest one being I don't get the full 45mp image with the adapter. The camera crops the image. I also tried a Sigma and a Tamron wide angle. Both lenses were severly vignetted. In addition the Tamron produces chromatic aberrations which rendered the lens unusable.

Really? In case the camera crops the image the lens is an APSc-lens. I owned an EOS R, now the R6 and I only own full frame lenses (Canon TS-E 45, TS-E 17, 135/2.8, 180/3.5, Zeiss 100/2 and some more). Never been a problem.

I do guess those lenses are for APSc. If they aren't, I'd return the adapter, maybe it's damaged so the information about the lens isn't transferred correctly.