tbh, I totally get the struggle. Ive tried many wide lenses on my a6400 over the years, and finding that sweet spot between size and low-light performance is tricky! Honestly, for under $400, you have some solid picks but they all have trade-offs. Here's how they stack up in the real world: - Sigma 16mm f/1.4 DC DN Contemporary for Sony E: The image quality is literally incredible, but it's highkey a brick. If ur walking all day, you'll definitely feel the weight.
- Samyang AF 12mm f/2.0 E: Make sure you look at the AF version!! It solves your manual focus worry and it's sooo much more portable than the Sigma. Perfect for those tight urban alleys.
- Sony E 20mm f/2.8: The ultimate 'stealth' lens. It's basically flat, but maybe not wide enough for what you want? In my experience, the Samyang 12mm AF is the best balance of price and weight for street stuff. It's reallyyy fun to use at night too. gl! 👍

Ngl, if you're looking at the technical side of things, you should really just look at the autofocus primes coming out of Viltrox lately. They've been doing some impressive work with their optical formulas, specifically targeting the shorter flange distance of the E-mount to keep things compact. From a data perspective, their newer glass shows really decent MTF curves even wide open, which is what you need for those blue hour shots. Basically, you cant go wrong with any of the Viltrox wide-angle primes for Sony APS-C. They use STM motors that sync up perfectly with the a6400 tracking, and the chromatic aberration control is way better than what you usually see at this price point. Plus, they tend to be much lighter than the massive bricks other brands make, so your wrist wont be killing you after a full day of shooting urban scenes. Just pick any of their wide options and you'll be happy with the balance of sharpness and portability tho.

Like someone mentioned, the trade-offs we have to make these days are just exhausting. I have been dealing with this exact same headache for years with my a6400 and it really feels like the big manufacturers have just checked out on us budget shooters.

• The price of decent glass has gone through the roof while the build quality feels cheaper than ever.
• Why is it so hard to get a compact, fast wide-angle that doesnt feel like a toy or weigh as much as a literal brick?
• It is honestly such a scam that we have to choose between missing focus on a manual lens or breaking our necks with a giant prime just to get a decent blue hour shot.
• In my experience, the long-term reliability of these cheaper alternatives is just not there... I have had mounts get loose and AF motors start clicking after only a few months of heavy street use. It drives me crazy because we just want to go out and shoot without feeling like we need a second mortgage or a gym membership just to carry the gear. Glad it is not just me feeling this way tho... honestly its ridiculous.

Honestly its just ridiculous how hard it is to find a good balance these days. It drives me crazy that the big camera companies seem to have totally forgotten about the budget-conscious street shooters. Like, why does every decent wide-angle have to cost as much as the camera itself? It feels like such a scam when you're looking for something that wont weigh you down during a long day of walking but still gives you that fast aperture for blue hour. You're basically stuck between spending way too much money or settling for gear that honestly feels like a toy. Its so frustrating because the a6400 is such a great little body, but finding affordable, high-quality glass that actually fits the compact vibe is getting impossible. Companies just dont seem to care about us anymore, they're too busy chasing the high-end pros with deep pockets... it sucks.