Hey! Congrats on the C70, it’s seriously such an amazing camera! I’ve been shooting with mine since it launched, and honestly, it’s a total beast for events.

For your situation, I would suggest going native. While I love the "full-frame look" of the booster, the native RF communication is just way more reliable when things get hectic. Here’s what I recommend:

* Canon RF 24-70mm f/2.8L IS USM: This is my absolute workhorse. The Dual Pixel AF is incredibly sticky, and the internal stabilization is a lifesaver for handheld shots.
* Canon Mount Adapter EF-EOS R 0.71x with the Canon EF 24-70mm f/2.8L II USM: Go this route if you’re frequently in SUPER dark venues. That extra stop of light effectively turns your f/2.8 into an f/2.0, which is fantastic for low light.

In my experience, having that native Canon RF 24-70mm f/2.8L IS USM makes run-and-gun work so much less stressful because you aren't worrying about the adapter wiggling or the AF hunting. Hope this helps! Good luck with the new rig!

Honestly, I'm super happy with my current setup. For run-and-gun, the Canon RF 24-105mm f/4L IS USM is my favorite workhorse because the extra reach is huge for events. However, if you're torn, the Canon RF 24-70mm f/2.8L IS USM is definitely better for low light. Adapted glass like the Canon EF 24-70mm f/2.8L II USM with the booster works well, but native RF autofocus is just way more reliable when things get hectic!

Just found this thread and man, I am literally in the exact same boat even after shooting on C70s since they basically shipped! It is such a massive headache trying to decide between the two workflows because both have these huge technical trade-offs that drive me crazy every time I prep for a shoot. I have been a Canon shooter for over a decade and this dilemma is basically the bane of my existence lately for a few technical reasons:

• The balance between sensor coverage and focus speed is a nightmare. Speed boosters give that S35-to-FF field of view but you lose that micro-adjustment precision in high-speed tracking that you get with native glass like the Canon RF 24-105mm f/2.8 L IS USM Z.
• Physical ergonomics change completely. Adding an adapter and a heavy EF zoom like the Canon EF 24-70mm f/2.8L II USM shifts the center of gravity and makes gimbal work a total pain.
• Meta-data communication issues. Sometimes iris info or lens correction data doesn't pass through as cleanly on adapted glass which messes with my post-production logging. Honestly, even after years of professional work, I still havent fully committed to one side myself because the struggle is so real! It feels like you are always sacrificing one amazing feature for another.

> I mainly do run-and-gun event work. Do you guys prefer native RF lenses for the autofocus, or is adapted glass the way to go?

Curious about one thing: what's your typical delivery requirement and lighting situation like for these events? I've been shooting with the C70 since it dropped, and honestly, I've had a bit of a love-hate relationship with the speed booster route.

I started out trying to save cash by using my old EF glass with the Canon Mount Adapter EF-EOS R 0.71x. It definitely gives you that full-frame depth of field, but man, in the heat of a fast-paced wedding or corporate gig, the autofocus can occasionally hunt just enough to be annoying. FWIW, native glass like the Canon RF 24-70mm f/2.8L IS USM is way more reliable for tracking faces when you're moving fast.

That said, if you're on a budget, adapted EF glass is a steal right now. Are you mostly on a gimbal or handheld? That might change which way I'd lean for your specific workflow!

Tbh, the biggest technical hurdle I ran into when DIY-ing my C70 setup was the back-focus calibration on my adapted lenses. If you’re coming from a professional cine background, you know how critical flange focal distance is, but many event shooters just slap glass on and wonder why their zooms aren’t parfocal anymore. I spent a whole afternoon with a Siemens star chart adjusting the seating of my mounts to get it perfect. It’s totally doable yourself if you have the patience, and it makes adapted glass feel way more high-end. I actually ended up preferring the Canon RF 15-35mm f/2.8L IS USM for most of my indoor event work tho. Even with a booster, some older EF lenses just don't resolve well enough at the edges on that 4K DGO sensor. The RF glass is soooo much sharper wide open because the rear element is physically closer to the sensor, which basically simplifies the optical path. If you’re a technical geek like me, you’ll appreciate the 12-pin communication too—it handles metadata for post-stabilization and DLO in-camera way better than legacy glass. Basically comes down to if you want to spend time bench-testing your gear or just shooting.

I kinda agree with the general “native is simpler” vibe, but I’m not 100% sure it’s always the best *value* move right now. Like, if you look at the market, RF video-leaning zooms tend to hold price pretty hard and there aren’t tons of third‑party options yet (compared to Sony E / L‑mount where you can shop around a lot more). EF glass is a way more mature ecosystem, and used prices are pretty competitive… but the trade is extra complexity (adapter/booster, more points of failure) when you’re sprinting around events. So I’d frame it as: are you optimizing for reliability or for flexibility/cost? Also, do you need consistent focus breathing behavior or parfocal-ish behavior for live moves? IIRC that can matter more than “full-frame look” on the C70 for run-and-gun.

Can confirm

Building on the earlier suggestion, I have been really satisfied with how the setup handles during long event days. Honestly, I have no complaints with the performance lately, it just works and the results have been great. To give you a better steer tho, are you planning to use this on a gimbal most of the day or are you strictly handheld? Also, what is your actual budget for this lens right now? Knowing if you are looking for one do-it-all piece of glass or if you have some wiggle room to build out a kit would really help narrow things down for your specific workflow.

> Do you guys prefer native RF lenses for the autofocus, or is adapted glass the way to go? I am literally in the same boat right now, just staring at my bank account after buying the C70 and feeling the sting. I'm so worried about compatibility issues that I have been paralyzed on what to buy next. I spent hours looking at the Sigma 18-35mm f/1.8 DC HSM Art as a budget option with an adapter, but then I read a horror story about the Viltrox EF-EOS R Mount Adapter losing signal during a live event. It is like, do I risk it to save a few hundred bucks or just keep saving for the Canon RF 24-105mm f/4L IS USM? Honestly being on a tight budget is rough because one wrong purchase could basically ruin a shoot. I would definitely be careful with third-party adapters if you are doing run-and-gun stuff where you cant just restart the camera mid-vow or whatever. Just wanted to jump in and say you are not alone in this headache... it is a lot of money to drop when you are just starting out.

@Reply #9 - good point! It is totally normal to feel a bit paralyzed when you are staring at those price tags, especially after a big body purchase. I have been thinking about this for a bit and I actually disagree slightly with the sentiment that value should be the deciding factor here, though I totally understand why people go that way. I tend to be much more conservative because I have seen how quickly things can go sideways. You really have to be careful about the mechanical stress you're putting on the mount during a long day of handheld work. This whole discussion honestly reminds me of a shoot my old mentor did years ago when he was trying to save a few bucks on a documentary in the desert:

• He brought a bunch of adapted glass because it was cheaper than renting native.
• The heat caused the metal in the cheap adapters to expand just enough to seize up.
• He ended up having to use a hacksaw to get one of his favorite primes off the body. It was a complete nightmare and he lost about two days of production time just dealing with the hardware failure. Every time I think about adapting glass for a professional job, I just see him standing there in the sand with a saw... just makes you realize how much can go wrong when you add extra variables to the mix.