Forget the 15-30mm for the R7. On a crop sensor, it starts at a 24mm equivalent which just isnt wide enough for those massive Zion canyon walls. The Canon RF-S 10-18mm f/4.5-6.3 IS STM is the right tool here despite the plastic feel. Flare is actually handled pretty well for a lens this cheap, tho you will see some ghosting if the sun is hitting the front element directly.

• True ultra-wide field of view (16mm equivalent)
• Well under your $600 budget
• Super light for hiking all day The build feels like a toy because its plastic, but the optics are sharp enough for any landscape shot. If you are worried about flare, just pick up a lens hood with the money you save. Its a much better value than the 15-30 for your specific camera body.

Building on the earlier suggestion, I've unfortunately had issues with the build quality of those new RF-S lenses. They're honestly not as good as expected for rugged hiking. Zion is no joke. I'd skip the toy feel and go with:

• Canon Mount Adapter EF-EOS R
• Canon EF-S 10-22mm f/3.5-4.5 USM The 10-22mm is way sturdier than the 10-18mm. Flare is manageable, and it's much more reliable when you're scrambling over rocks.

Building on the earlier suggestion, what kind of tripod are you taking? Zion lighting is totally brutal tho. I once took a budget setup through the Narrows and the flare off the canyon walls basically ruined my best shots. I learned the hard way that saving cash often means losing the shot to haze. Just be careful with those flimsy mounts in a sandy, dusty environment...