Honestly, I would suggest the Viltrox EF-EOS R Mount Adapter for $50. It's basically identical performance-wise, but be careful with heavy L glass... might feel a bit loose tbh.

Curious about one thing: what glass you using?

1. Fotodiox Pro EF-EOS R Mount Adapter: Solid build.
2. Metabones Canon EF to RF Lens Mount T Adapter: Premium feel.

Fotodiox is SO reliable tbh!

stumbled upon this today! In my experience, I tried a budget Meike once... i think it was okay? AF was snappy on my R6, but the mount felt kinda sketchy with my heavy 70-200. idk if it'll hold up for pro work tho. TL;DR: They're amazing for the $50 price point with light glass, but maybe stick to Canon for the heavy stuff for better reliability!!

sooo i actually ran into this exact same issue when i first moved over to the R6. i was shooting a wedding and my official mount vanished into thin air... i had to grab a generic one from a local shop just to finish the gig. honestly, i think most of these third-party ones are basically fine for standard shooting because the protocol for EF-to-RF is essentially a straight pass-through. iirc, there's no actual signal conversion happening, just a physical extension of the pins.

not sure if this applies to EVERY brand, but i did notice that on some cheaper ones, the weather sealing is non-existent compared to the Canon version. that might be where the 'light leak' rumors come from, you know? personally, ive used a Commlite for months and the AF speed felt identical, even for high-speed tracking. if ur worried about heavy L glass, maybe look for one with a detachable tripod foot to take the strain off the mount. basically, the lesson i learned is that unless ur shooting in a monsoon, the third-party stuff is highkey a steal. dont overthink it!

Ok so I saw this earlier and I've gotta say... I've had a different experience than the previous posters. I totally get wanting to save cash, but honestly, putting heavy L-lens glass on a budget adapter makes me super nervous for pro work.

I tried the Viltrox EF-EOS R Mount Adapter everyone mentions, and while it works fine for light primes, I ran into some technical issues once I started using my heavier gear:

1. **Mechanical Play**: After a few weeks, my Canon EF 70-200mm f/2.8L IS III USM had a tiny bit of "wiggle" in the mount. If that mount sags even a millimeter, you risk losing sharpness or damaging the pins.
2. **Weather Sealing**: Most third-party ones lack the rear rubber gasket. If ur shooting in dust or light rain, that's a huge risk for ur R6 sensor.
3. **Pin Communication**: I noticed occasional communication errors that required a restart.

I'd actually suggest holding out for the Canon Control Ring Mount Adapter EF-EOS R. It feels way more solid and the extra ring is actually super useful for ISO. It sucks it's pricey, but it's basically insurance for ur gear lol. Peace!

Just saw this thread and wanted to chime in! Tbh, I've been using a mix of things since I got my R6. The thing about these adapters is that internally, they're basically just "dumb" extensions because the EF and RF pins talk the same language. That's why AF usually feels snappy right out of the box. But what I've noticed after about a year of heavy use is that the *internal coating* on some of those cheaper off-brands starts to flake or it isn't matte enough. I had this one generic adapter—I think it was a Commlite EF-EOS R Mount Adapter—and it worked great for months, but then I started getting weird internal reflections when shooting toward the sun. It’s like the black paint inside wasn't quite right? Also, something I didn't think about at first was the weather sealing. I'm still kinda new to the mirrorless world, but I noticed my native glass has that rubber gasket that the cheaper adapters sometimes skip or use a really stiff plastic for. If you're shooting in dusty places or light rain, that might be something to look at. It's not just about the pins connecting, it's about keeping the gunk out of your sensor over the long haul. Does anyone else notice if their third-party ones have a proper rubber seal?

Regarding what #6 said about "Just saw this thread and wanted to chime...", i have been using an off-brand one for a long time and i am honestly so satisfied with it. It works well for my glass and i have no complaints about the speed or anything. Honestly though, there are so many videos on this that it is easier to just search for it. Just go on youtube and type in canon ef rf adapter comparison and you will see dozens of side-by-side tests that show the autofocus and everything. I saw a really good one a few months back that convinced me to skip the official canon one. Just check the canon groups on reddit too, they have whole lists of which ones are best for heavy lenses. It is way more info than i can give here lol.