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.

I won't make this review lengthy, because it's all been said before, but I will qualify myself by saying that I depend on photography for approximately half of my income, and I recently purchased this lens after many hours of online research. I own a Canon 7D, and I was looking for a lens that would fall into the wide/portrait range with the 7D's 1.6x crop factor. This lens was bought as a replacement for my old Tamron 28-75, which was a respectable lens. The Canon 17-40 has thus far been a very solidly built, light, fast-functioning lens. It autofocuses VERY quietly with its ultrasonic motor, and the autofocus is very accurate. On the 7D, I have found it to be a capable portrait lens at 40mm, as well as a great lens for interiors. I bought it as a complement to the Canon 70-200L, for a lightweight kit, and while I am missing the 41-69 focal range, I haven't really needed it. The lens produces VERY SHARP photos, and is much more reliable in quality than the Tamron. I would definitely recommend it to 7D users wanting a versatile walkaround lens, or to full frame users looking for an ultrawide with great sharpness.

Not a better portrait lens for the money available

Extremely pleased with this lens for video and photos. I am using a Canon RP so I have to use an adapter but I am having no issues at all.

Bought this Nifty Fifty for portrait and astrophotography. A very well built and affordable Canon lens EVERY photographer should have. Easy to use and works quite well. Am completely satisfied with this purchase.

I am using this lens for Canon M50 Camera. You will need EOS adapter. I have attached 3 photos taken with this lens.

I purchased a Canon FD to Leica M adapter in order to get some more use out of my 17mm Canon lens. I’m pretty impressed with it so far. It seems considerably better quality than the cheap imported adapters, and not as expensive as a Novoflex. The lens hooks up solid and it feels solid on the camera body. I will most likely try some of their other adapters as necessary.

As a Canon DSLR shooter this adapter is a must for owning the EOS M. It's really the only reason why I bought the EOS M. I love the 22mm f2 that comes with it, but being able to use my nearly $10k worth of lens on this makes it a steal. I believe without this adapter the camera is very limited. The adapter fits the camera and lens nicely. I personally feel that the lense attaching to the EOS M feels strange, tight compared to all my DSLRs, but this adapter and lens are snug once attached, and that's what matters.