50mm f/1.2 GM might be overkill for street photography honestly. It's heavy, expensive, and draws attention. I'd go with something more compact like the 40mm f/2.5 or even the 55mm f/1.8 if you can find one used. Street photography is about being nimble and unnoticed.

Can confirm

For street photography with the Sony a7CR, consider these compact and lightweight lenses:

1. Sony FE 24mm F1.4 GM - Excellent image quality and great for low light.
2. Sony FE 20-70mm F4 G - Versatile zoom range, lightweight, and weather-sealed, ideal for urban settings.
3. Tamron 28-75mm F2.8 Di III VXD G2 - A good balance of size, weight, and performance.

These options will help you capture stunning street shots without the bulk of heavier lenses.

Sony FE 35mm f/1.4 GM.

Sony FE 20mm f/1.8 G, I love this lens.

Just saw this and figured I would chime in. If you are coming from that Sigma 18-35 beast, you are gonna love how light the a7CR can be with the right glass. I usually stick to native lenses for the best reliability and autofocus speed, but some third party stuff is getting really good now too.

• Sony FE 40mm f2.5 G is basically made for your camera. It is tiny, has a dedicated aperture ring, and the weather sealing is great for peace of mind when it gets drizzly in the city.
• Sigma 35mm f2 DG DN Contemporary is a decent alternative if you want a faster aperture. It is part of their I-series so it is all metal and feels very sturdy, though it is slightly heavier than the Sony G compacts.
• Sony FE 35mm f1.8 is a bit of a classic. It is not as premium feeling as the others but the autofocus is rock solid and it is very predictable for everyday use. Sony's compact G lenses are probably the safest way to go if you want to stay discreet in NYC. They just work without any fuss. Street shooting there is a blast, let me know if you need more help narrowing it down.