I have spent a lot of time with the R system and, frankly, choosing a lens for the R5 Mark II comes down to reliability and consistency. For indoor wedding work, the Canon RF 24-70mm f/2.8L IS USM is my primary recommendation. I have been very happy with its performance in low light. While the weight is a factor, the constant f/2.8 aperture is essential for keeping your shutter speeds high enough without destroying your image quality with noise. It is a workhorse that has never failed me and the results are always professional. No complaints at all regarding the build quality or autofocus speed. In contrast, the Canon RF 24-105mm f/4L IS USM is an excellent lens for general travel or outdoor events, but it is just too slow for professional reception coverage. You will find yourself struggling once the sun goes down or the venue lights dim. It works well for hobbyists, but for your specific needs, it is a risky choice. I always suggest prioritizing light gathering over extra focal length when your reputation is on the line. If you want something even faster, the Canon RF 28-70mm f/2L USM is incredible, but it is basically a gym weight. Stick with the 24-70mm for the most reliable balance. TL;DR: The Canon RF 24-70mm f/2.8L IS USM is the safest and most professional choice. The f/2.8 aperture is non-negotiable for wedding reliability.

Jumping in here. Whats your max ISO tolerance? I'm very satisfied with the Canon RF 24-105mm f/2.8L IS USM Z specs.

• Constant f/2.8
• Dual Nano USM
• Internal zoom design

The best all-around zoom for that camera is definitely a fast L series glass from Canon! Wow, congrats on the R5 II, that body is an absolute beast for weddings. Honestly, you just gotta stick with the pro-grade stuff. The engineering they put into those lenses is just insane lately, especially how they handle chromatic aberration and spherical distortion. It makes such a huge difference when youre shooting wide open at a reception!

• Look for a fast constant aperture to keep your ISO down
• Check for weather sealing so you dont panic during rain
• Buy used to save cash Basically, just grab a high-end zoom from the L line and youll be set. You really cant go wrong with their pro glass. The contrast and micro-contrast are just fantastic and the build quality is totally worth the extra weight, tho your arms might feel it after 10 hours!