Listen, I've been through this exact gear panic when I moved to a higher-res sensor. Tbh, if you already have the Canon RF 24-105mm f/4 L IS USM, you are probably fine. I know everyone raves about the Canon RF 24-70mm f/2.8 L IS USM, but for a trip like Iceland, that f/2.8 aperture is gonna be way less important than having that extra reach on the long end for landscape compression. In my experience, that 24-105mm holds up way better on 45MP sensors than the internet experts give it credit for. Over the years, I've realized most people can't even tell the difference once the photo is edited and compressed for the web. Here is why I'd stick with it for now:

• Weight: Youre gonna be hiking a lot. Carrying that heavy 2.8 zoom all day gets old fast when youre climbing basalt columns.
• Weather sealing: The L series 24-105 can handle the mist from those waterfalls and the unpredictable Icelandic rain like a champ.
• Budget: Since you mentioned being tapped out, spending 2k+ on a lens that really only gives you one extra stop of light feels like a mistake right now. If you really want to save cash but want a change, maybe check out the Canon RF 24-240mm f/4-6.3 IS USM. Its surprisingly sharp for a non-L lens and very versatile, tho it lacks the weather sealing of your current glass. Honestly, just take the lens you already have and use your remaining money on high-quality filters or a really solid tripod for the Northern Lights. Youll be much happier when youre actually out there shooting and not worrying about your bank account.

^ This. Also, buying that heavy 2.8 zoom is a fast track to disappointment when you realize 70mm is too short for most of the scale in Iceland anyway. I had issues with the bulk on my last trip and honestly it's just not as good as expected given the crazy price. Unfortunately, people get obsessed with f/2.8 when they should be worrying about focal range. If you're tapped out on cash, just keep your 24-105. It's plenty sharp for the R5II if you're stopping down for landscapes. If you absolutely have to buy something else, maybe look for a Canon RF 100-400mm f/5.6-8 IS USM. It's surprisingly decent on the 45mp sensor and gives you the reach you'll actually want for those distant peaks. Dont fall for the pro lens trap if your budget is gone.

Re: "Same boat, watching this"

• Jumping in to agree with what the others said about the weight. I have been shooting the R5 series since day one and the Canon RF 24-105mm f/4L IS USM is still a total workhorse. The new sensor is great, but it doesnt mean you need to dump perfectly good glass for the latest hype. Couple of quick tips for your prep:
• Stick with the 24-105 and look at the Canon RF 14-35mm f/4L IS USM instead. You are gonna want that extra width for the scale of the waterfalls and canyons.
• Grab a solid filter like the B+W 77mm Master Circular Polarizer MRC Nano. Dealing with spray and glare is the real challenge there, not the lens sharpness. The 24-105 is plenty sharp enough for the Mark II. Youll mostly be stopped down to f8 or f11 anyway for landscapes, so f2.8 is kind of a waste of money and muscle for a trip like this.

> Is the RF 24-70 2.8 actually worth the extra weight Late to the party but in my experience, heavy glass usually stays in the bag. Tried that route years ago and my back still hates me... I stick to lighter setups now.

Can confirm this works. Did the same thing on mine and its been solid ever since.

Saw this earlier but just now getting back to the thread. Before I weigh in on the glass, I gotta ask... what is your plan for a tripod? Are you shooting handheld mostly or do you have a serious setup for long exposures? In my experience, the sensor resolution isnt the problem, it is the environment. Iceland will chew up your gear if you arent prepared. A few warnings from someone who has been there:

• The wind is brutal and will shake anything that isnt weighted down or heavy duty.
• Salt spray and volcanic dust are everywhere, and they will get into every crack of your gear.
• Constant lens swapping in those conditions is a massive risk for getting grit inside the body. Tbh, focus on the weather sealing and stability first. If you're shooting landscapes, you will be stopped down to f/8 or f/11 most of the time anyway, so that f/2.8 might just be extra weight you dont actually need. Keep it simple and stay reliable.

Regarding what #4 said about "Saw this earlier but just now getting back..."

• I really felt that part about the environment being the real enemy. I actually switched over from a high-res Sony setup a while back thinking the Canon glass would be a total game changer for the R5 series, but honestly, it was kind of a letdown at first. I had issues with the weight vs performance ratio and found some of the hyped lenses just not as good as expected when you're actually out in the mud and rain. The R5 Mark II is a beast, but that 45mp sensor is super unforgiving compared to your old R6. If your technique isnt perfect or the wind is shaking your setup, even the priciest 2.8 zoom is gonna look soft. Unfortunately, I learned that the hard way during a coastal shoot where my pro glass just couldnt keep up with the vibration and I missed the reach of my slower zooms. Before you dump more money tho, are you mostly shooting wide landscapes or do you find yourself needing that tight 105mm reach for compression? Also, is low light performance for the aurora a major priority for you, or are you strictly a daytime shooter?

Same boat, watching this