Honestly, I took the Canon RF 24-105mm F4 L IS USM to Tokyo a few years back and left feeling pretty disappointed. Sure, the reach is nice, but the low light performance just isnt there for night street shots. I had issues with handshake blurring even with the R6 IBIS because I had to push the ISO way too high.

• The f4 aperture is a struggle once the sun goes down.
• Youre gonna miss focus on moving subjects if it gets dark. Since the Canon RF 24-70mm F2.8 L IS USM is way out of your budget, grab the Canon RF 35mm F1.8 Macro IS STM instead. It is tiny, cheap, and the fast aperture is a lifesaver for night scenes. Just carry that alongside your kit lens and thank me later.

Like someone mentioned, low light is the real killer here, but dropping thousands on the f2.8 zoom is overkill if your budget is already strained. Honestly, if you want sharp street shots at night without selling a kidney, just grab a fast prime to toss in your bag. Itll save your trip and your wallet.

• Canon RF 35mm F1.8 Macro IS STM - super compact and perfect for street stuff
• Canon RF 50mm F1.8 STM - dirt cheap and way faster than any zoom Take the zoom you already have for daytime stuff, then switch to the prime once the sun drops. You really dont need a zoom for night street photography anyway. Just be careful with wide apertures, make sure you nail that focus. You might want to consider just packing a light Manfrotto Compact Action Tripod if you really need to stop down for those long exposure city shots.

Totally agree with the previous poster about the limitations of that f4 aperture when the sun goes down. It gets pretty frustrating when you are trying to capture the neon lights of Shinjuku and you just cant keep your shutter speed up without cranking that ISO into the noise zone! If the budget is tight, you might want to look into picking up a small prime instead of blowing your money on one heavy zoom. Carrying a compact lens makes street photography way more enjoyable and less conspicuous in crowded areas like Shibuya. Here is what I would suggest instead of the expensive zoom:

• Bring a fast prime lens for those late night walks since the wider aperture is a life saver.
• Check out the website dpreview for their sample galleries to see exactly how high ISO looks on your sensor.
• Use a small tabletop tripod or even just a beanbag if you want to do long exposures without the bulk of a full setup. Honestly, having that extra stop of light is way more important than the convenience of a zoom lens at night. You will get way sharper shots, and honestly, moving your feet is the best way to get a better composition anyway. Have an amazing time in Japan, it is seriously a photographer's dream!