So I have spent a lot of time wandering around with the A7C and honestly the balance is everything. If you are worried about reliability when you are out in the crowd, you really cant go wrong with the G series primes. I have tried a bunch and keep coming back to them because the weather sealing and AF speed are just rock solid. I actually think the Sony FE 40mm f/2.5 G is the secret weapon for street photography. It is tiny, built like a tank, and the 40mm focal length is that perfect middle ground between 35 and 50. It doesnt look like a pro lens so people dont get as nervous when you are nearby. The main downside is that f/2.5 aperture... it is okay for evening, but if you are shooting in pitch black you might struggle compared to something faster. If you need that extra light for late night shots, the Sony FE 35mm f/1.8 is the practical workhorse. It is a bit longer than the G series but still very light. The autofocus is basically instant and super quiet which is huge for being discreet. I have found some third-party lenses can occasionally hunt in low light or have weird firmware glitches, so for total reliability I usually stick with native glass for street stuff. Lastly, if you really want that 50mm look without the bulk, look at the Sony FE 50mm f/2.5 G. It has the same compact housing as the 40mm. Personally, I think 35mm or 40mm is better for busy cities because you can always crop in, but you cant always step back when things get crowded.

I totally agree that sticking with something that has reliable autofocus is key, especially since you're already loving how the A7C handles. If you are watching your budget tho, I would suggest looking at the Samyang AF 35mm f/1.8 FE. Its usually much cheaper than the Sony version and weighs almost nothing... great for avoiding that wrist fatigue you mentioned. One quick tip: if you're torn between 35mm and 50mm, definitely look at the Sony FE 40mm f/2.5 G. It's basically the perfect middle ground and probably the best match for the A7C's compact size. Its tiny, discreet, and has a physical aperture ring which makes manual control so much faster when you're moving through different lighting. Honestly, it stays on my camera 90 percent of the time now because its just so convenient and doesnt draw any unwanted attention.

I totally agree with the G series recommendation for size, but if you're comparing costs, the Sigma 35mm f/2 DG DN Contemporary is a hidden gem. I've used it alongside the Sony FE 35mm f/1.8 and the Sigma feels way more premium for the money. Having an actual aperture ring is a lifesaver when you're trying to be quick in a crowd. Definitely worth looking at before you pull the trigger on native glass.

I'm not sure but I think the 35mm native glass is the safest bet. Someone told me they're just more reliable for the autofocus, which is what I'd want too.

Just caught this thread today and honestly I wanted to jump in with a bit of a warning before you spend your cash. One thing people usually overlook when they switch to a compact body like the A7C is how much technical reliability actually matters when you are out there all day. I would be really cautious about going too cheap with some of the third-party glass just to save a few bucks. I have seen way too many people deal with weird autofocus hunting or even communication errors where the camera just stops recognizing the lens right when you are about to hit the shutter. It is incredibly frustrating when you are in the middle of a busy city and miss a shot because of a software glitch. Also, keep an eye on weather sealing. If you are shooting street, you are gonna be dealing with dust, exhaust, and maybe a bit of rain. A lot of the ultra-compact pancake lenses skip out on the rubber gasket at the mount. Without that, you are basically inviting gunk into your sensor chamber. Another technical thing to watch for is the focus motor type. Some older or budget primes use stepping motors that are kinda noisy and slow. If you want to be discreet, you really want something with linear motors so you are not clicking and whirring every time the camera grabs focus. Better to spend a bit more for something with internal focusing too... it keeps the dust out and keeps the lens profile consistent. Just my two cents from being burned by cheap gear before.