Honestly, the hunting on adapted glass is a total mood killer. If you want reliability, the Canon RF 24-105mm f/4L IS USM is basically the safe bet for an all-arounder. It just works. The focus is night and day compared to EF lenses on an adapter, especially with how fast the R5 II is. It should handle those soccer games way better... no more blurry shots while the lens searches for focus. Since you have $2,300, you could also look at the Canon RF 24-70mm f/2.8L IS USM. Its usually right at the top of that budget but it is a solid piece of kit. Tbh, for Glacier, having that extra reach to 105mm is pretty useful for framing mountains. I would probably stick with the f/4 for the weight savings and reliability. It is a decent option that wont let you down on the trip.

Been thinking about this and I unfortunately have to disagree. @Reply #1 - good point on the focus speed, but f/4 was not as good as expected for freezing soccer action. I had issues with noisy shots in Glacier lighting too. Methodically, the Canon RF 24-70mm f/2.8L IS USM is the superior choice here. The Nano USM motors are technically faster and more reliable for tracking sports.

TL;DR: Grab the Canon RF 24-105mm f/2.8L IS USM Z if you can stretch the budget or hunt for a deal, but for pure tracking speed on the R5 II, stick to native glass only! Honestly, the hunting you're seeing with EF glass is purely down to the protocol translation through the adapter. Youre losing frame data, which kills the R5 II's incredible AF tracking algorithms. For Glacier landscapes, you need the micro-contrast native RF glass provides. If the 24-70 f/2.8 is too pricey, look at the Canon RF 24-105mm f/4L IS USM. Just make sure your shutter speed is cranked up for that soccer action! The R5 II sensor is super sensitive, so don't be afraid to push the ISO. You'll get tack-sharp shots every single time without that annoying hunting. Native mount is basically magic for tracking performance!

Honestly it is facts. Jumping in here because the whole state of gear right now is just disappointing. You spend five grand on a Canon EOS R5 Mark II and then you're basically forced to spend another two grand plus just to get a lens that doesn't hunt like crazy... it's a total scam. Canon knows exactly what they're doing by locking down the mount. You look at Sony and at least they have third-party options that don't cost a literal kidney, but here we are stuck in this closed ecosystem paying premium prices for stuff that feels more like a tech gadget than a professional tool. I've been with Canon forever but the way they've priced the RF lineup is just insulting to long-time users. It's like they don't even care about the hobbyist or the semi-pro anymore, it's just about squeezing every cent. Honestly, it's ridiculous how much more we're paying now for incremental focus improvements that should've been standard. It drives me crazy.

Honestly, if you are heading to Glacier with that gear, just make sure you check your firmware on the camera body before you leave. I have seen way too many people get frustrated with brand new native glass because the body was running old software. It makes a massive difference for the autofocus tracking reliability. Also, be really careful about buying used gear from random sites to save money since you are right on the edge of your budget. If you grab a lens that has been dropped or had the internal elements misaligned, no amount of modern tech will fix your focus issues. Spend the extra bit for a new one or at least verify the serial number with a reputable shop. You definitely dont want to be dealing with gear failure in the middle of a national park hike.

Facts.

To add to the point above: the technical performance of the Canon RF 24-70mm f/2.8L IS USM is what you actually need for those soccer games. I have been very satisfied with the dual Nano USM motors because they provide the necessary torque to keep up with the R5 II sensor readout. The EF adapter often introduces just enough latency to cause that hunting you're seeing during high-speed tracking, whereas the native RF mount communication is nearly instant. Quick tip: since you are heading to Glacier, dont forget to enable the in-camera lens aberration corrections. It really optimizes the peripheral illumination and distortion for those wide landscape shots without needing heavy post-processing. I also suggest checking the refurbished listings directly from Canon; I saved a few hundred bucks on my copy and it has been flawless. It works well for basically any scenario where you cant afford to miss focus.

To add to the point above: the debate is basically reach versus speed. Unfortunately, I had issues with f/4 in dim light, and it was not as good as expected for freezing soccer action...

• Canon RF 24-105mm f/4L IS USM: Better for Glacier landscapes.
• Canon RF 24-70mm f/2.8L IS USM: Essential for sports reliability. Honestly, dont get the f/4 if soccer is a priority. Its just gonna lead to more frustration.