I recently decided to make the switch from a Canon DSLR to a Canon R mirrorless. It was easy to learn since I'm already used to Canons. I bought the EF to RF adapter (with the adjustable ring) so I could use my DSLR lenses with it. My only complaint is that Canon should give you the adapter free (they used to!) when you buy the camera. So far, it's taking good photos, and I decided to buy the kit lens that goes with the camera, so I can use it for all-around use when I'm out and about. I have a very nice Sigma macro lens that I bought at the same time, which needs the EF to RF adapter, but it takes very nice macros on this camera. I'm glad I bought it.

Absolutely perfect adaptation of EF lenses to my M series cameras. Basically feels like native lens. I have also used a third-party adapter, which is fine, but the AF takes just a little longer. Seems to have to micro adjust, whereas Canon adapter is just instantaneous.

I purchased this adapter along with the EOS M camera kit to use with my EF and EF-S lenses. After less than a week, I have been able to try out with the EF 50mm F1.4, EF 70-300mm L, EF-S 17-85mm, and EF-S 60mm lenses. The adapter fits perfectly. Same form and fit as the Canon extenders I have. The EOS M is of course made very tiny with any large EF lens. It creates a sort of 'pocket Rebel'. Of course, once you mate with the larger lens, this is no longer going to fit in anything less than a massive coat pocket. The combination of camera, adapter, and lens seems comfortable after brief handling. The EF 50mm was a very comfortable combination, the adapter does not add a very large amount to the overall combination. The upside to this adapter is if you already have a variety of EF and/or EF-S lenses. The image quality of the JPEGs, right out of the camera ranged from expected to stunning (the latter results obtainable with off camera studio flash strobe and soft box). The adapter was immediately a huge part of the EOS M camera purchase. I highly recommend it if you have other lenses. Again, the results I got with the EF-S 60mm macro (and studio lighting) were stunning. It transformed the camera from curiosity to studio prime. No problem using manual mode and Pocket Wizard. Include this adapter in your purchase and you won't be looking back.

Good lightweight camera. Great value and with lens adapter I can use all my EF lenses.

The adapter is good, delivery was also very fast, i got it just in 1 day.. But if you really wanna use EF or EF-S lens in mirrorless cameras, you have to keep in mind that the sharpness will decrease by a little amount and you you have to focus the subject very correctly, otherwise the picture will become blurry(specially for the prime lens)..

So you finally decided on getting the EOS M (it's flaws considered). I assume you are a canon user, have a couple of good (canon EF/EF-S mount) lens lying around and would like to be able to use those on you EOS M. Just like me, you love your canon dslr but sometimes wish you can travel light but still be able to enjoy the canon ecosystem that you have grown to love. If you are what I assume you are, get this lens adapter.I took a gamble and bought a "like-new" used from a seller at Amazon and was very happy with a purchase. For anything more than $150 I probably would think twice. But I am not taking a start out because of the price. This adapter handles every canon mount lens I threw at it. The build quality is nice. The design (the way it attaches to the eos m; the included, detachable tripod mount) is well thought of... just perfect.

It's an adapter - it allows me to put my EF glass on my EOS-M and they are fully functional when mounted. AF, Metering, aperture control - all good. Made of metal and I appreciate the tripod mount on it - handles my 70-200 f2.8 IS II without a problem although it looks pretty much like a rear lens cap when setup that way :)

My experience with Canon has been with the T3i, T6, 7dmk2 and 6dmk2. Each of these cameras were good in their own ways, but were not perfect. IQ was my biggest complaint, especially in low light.The R6 definitely has better IQ than these previous cameras and performs much better under low light conditions. The eye focus feature is helpful but takes some practice to learn. The images I get with my R6 compared to my 6dmk2 are noticeably sharper and show better tones overall.I am currently using only EF lenses on my R6 thanks to Canon's brilliant adapter! All my EF lenses work flawlessly on my E6 thanks to Canon's adapter. I'm waiting for Canon to release more primes in the near future to keep my R6 kit lightweight.As for the negatives, I'm not a fan of electronic viewfinders. Nothing beats the optical viewfinders of Canon's older dslr's. Also, a top lcd display would have been nice, but it's not a dealbreaker for me.Overall, I highly recommend the R6, especially if you own multiple EF lenses (just remember to purchase the adapter).