So I've tried many adapters over the years, and honestly, you gotta be cautious with heavy glass like that 70-200. - Canon Mount Adapter EF-EOS R: The safest bet. Solid build, perfect AF, and reliable weather sealing.
- Canon Control Ring Mount Adapter EF-EOS R: Great for workflow, though pricey.
- Viltrox EF-EOS R Mount Adapter: Honestly? I'd skip third-party. I've seen too many wobbly mounts and light leaks. Stick with Canon... better safe than sorry! cheers

In my experience, you have to be careful with third-party builds. - Viltrox EF-R2 Mount Adapter: It has the ring, but felt lowkey wobbly with my 70-200.
- Meike MK-EFTR-A Auto-Focus Mount Adapter: Good price, but the weather sealing is basically non-existent. Honestly, for pro glass like yours, I'd stick with the official Canon Mount Adapter EF-EOS R mentioned earlier. It is just way more reliable for heavy lenses and keepin' that weather sealing intact!

But honestly, if ur looking for a real workflow upgrade, check out the Canon Drop-In Filter Mount Adapter EF-EOS R with Variable ND Filter. It's a total game changer for heavy glass like the 70-200 since u don't have to mess with giant front filters anymore. It’s basically the only adapter that adds a feature RF lenses don't even have natively yet. Also, a quick DIY tip for that 'wobble' everyone fears: get a quality set of precision screwdrivers and check the mount screws yourself every few months. Even high-end adapters can loosen up slightly with heavy pro use. A 10-second self-service tightening keeps the connection rock solid and saves u from sending it in for professional repair or dealing with light leaks. Just be super careful not to strip the heads!!!

Seconding the recommendation above! Honestly, when you're lugging around that heavy 70-200mm, you *really* don't want to risk a wobbly mount. I've been super satisfied sticking with the official brand name stuff for my pro glass—it just works flawlessly and feels way more secure than the budget alternatives I've tried tbh. But before you drop the cash on the "fancy" version, I had a couple quick questions to see what fits your workflow. Are you usually shooting in harsh weather where sealing is a huge deal, or mostly in controlled environments? Also, do you actually find yourself needing an extra dial for things like ISO, or are you pretty happy with the dials on the camera body already? Just wanna make sure you aren't overspending for features you won't actually use tho!

Solid advice 👍

Saw this thread earlier and just had to jump in because congrats on the R6 Mark II! That camera is absolutely amazing and the jump from the 5D Mark IV is such a fantastic upgrade for autofocus and speed. I have been shooting EF glass on mirrorless since the very first R body launched years ago, and honestly, those old lenses still perform like magic on the new sensors! To help figure out which path is best for your kit, I have a couple of questions about your specific workflow:

• Do you find yourself needing to change exposure settings like ISO or aperture constantly without taking your eye off the viewfinder?
• Are you doing a lot of video or long exposure work where having internal filters would save you time? Knowing how you actually handle the gear in the field makes a huge difference when deciding if the extra features are worth the investment for your long-term setup.

Solid advice 👍