Testing a7S III high iso, filming at night only with moon light and few street lights far away.
Some screenshots can be compare between YouTube and the original file:
https://imgur.com/a/uBZeQ6i

Lens:
TTArtisan 21mm f1.5
Sony 85mm f1.8

Settings:
50fps 4K XAVC S 4:2:2 10bit 200Mbps
S-log3 with S-Gamut3.Cine
1/100s f/1.5 or f/1.8 iso 102,400 - 409,600
No Noise Reduction applied

Special thanks: 小冰