I totally get the frustration. I took that kit lens on a trip to Seattle last year and honestly the photos were such a grainy mess because it just couldnt handle the dim restaurants. It felt like a total waste of the R10 sensor. For your Japan trip, you really need better glass, but unfortunately the RF-S options are still a bit disappointing for low light.

• Canon RF-S 18-150mm f/3.5-6.3 IS STM: The range is great for architecture, but it is still way too slow when the sun goes down. I had issues with it in temples where it just didnt perform as well as I expected.
• Sigma 18-50mm f/2.8 DC DN Contemporary for Canon RF: This is much sharper and better for those street food shots. You lose the zoom reach but the constant f/2.8 is a lifesaver. Ngl, I would grab the Sigma even tho you lose the zoom.

> I need a single lens that can actually do it all because I am heading to Japan in three weeks You are gonna have the absolute best time!! I took my R10 to Tokyo last fall and honestly... the Canon RF-S 18-150mm f/3.5-6.3 IS STM was a total lifesaver. That zoom range is just fantastic for everything from wide street scenes to zooming in on temple carvings. Its so light I barely noticed it even after walking 15 miles a day through Shinjuku. Quick tip: since you're worried about low light, grab the Canon RF 28mm f/2.8 STM pancake lens too. Its tiny enough to fit in a jacket pocket and works wonders for those moody night shots in the alleys. Using those two together is the ultimate lightweight travel setup imo. You're gonna get some amazing shots!!

Honestly, I've been there and it really kills the mood when you're in a beautiful place like Japan. I remember walking through some dim temples in Kyoto last year with a slow lens and just feeling defeated because every single photo came out as a noisy mess. It felt like I was failing the camera sensor. Since then, I've become pretty protective of my gear choices because I just want things to work the first time without any fuss. I eventually settled on the Sigma 18-50mm f/2.8 DC DN Contemporary for Canon RF and I've been so satisfied with it. The technical side is basically this: your current kit lens closes up its aperture (the hole that lets in light) as you zoom, hitting f/6.3 very fast. That Sigma lens stays at f/2.8 no matter how much you zoom. It lets in way more light, which is exactly what you need for those street food stalls at night or dimly lit shrines. Its also sharp as a tack. It fits your budget perfectly and is incredibly light. I did those 20k step days in Tokyo and barely noticed it on my R10. If you absolutely need to see the top of a skyscraper from the ground, the Canon RF-S 18-150mm f/3.5-6.3 IS STM has more reach, but it wont help with the grain in low light like the Sigma does. For me, having that reliable f/2.8 was the safe choice so I didnt have to worry every time the sun started to go down...

I am dealing with the exact same headache and it is honestly so draining trying to find a solution that doesnt feel like a total gamble. I have been researching for about three months now for an upcoming trip and I still havent found anything that makes me feel confident enough to pull the trigger.

• I tried taking my current setup to a local indoor market last weekend just to see how it handled the dim lighting and the results were so messy I almost gave up on the spot.
• Every time I look at a potential lens, I start worrying about the build quality or if it is gonna be too heavy to actually carry for ten hours straight.
• It is just so frustrating because the R10 is such a capable little body, but I feel like I am constantly being held back by the lack of fast glass that actually fits a travel budget. I have been staring at different reviews for weeks and I am still just as stuck as you are... it is like every option has some massive flaw that makes it feel like a waste of money tbh.

This is exactly what I needed to hear. Youre a lifesaver honestly.

Re: "This is exactly what I needed to hear...." - it is a total game changer when you find a lens that actually keeps up with the r10 sensor. i have been using the Sigma 18-50mm f/2.8 DC DN Contemporary for Canon RF for a few months now and i am so satisfied with it. honestly, the 18-150 is okay for reach, but if grain is your main frustration, that f/2.8 aperture is what you actually need for japan. the way it works is basically keeping your iso way lower because the lens lets in about four times as much light as your kit lens at the long end. i did some diy comparisons at a local dim restaurant and the clarity is just on another level. it is super light, maybe even feels better balanced on the r10 than the bigger canon zooms do. you will be able to shoot those dim temples in kyoto without any of that annoying noise. it works well for everything from wide street shots to close up food photos. definitely check it out before your trip, you wont regret it.