You asked

Is the fujifilm gfx 50s ii good in low light?

I don't have a low-light test for the GFX 50S II, so I can't tell you how it compares at high ISO. What I can say is that a bigger sensor is where low light gets easier. My sensor sizes guide says the case for larger sensors is strongest in dim conditions. The body also has stabilisation built in, which helps you hand-hold in dim rooms.

Lens speed matters just as much. Look at fast primes like the Fujifilm GF 55mm f/1.7 R WR or the Fujifilm GF 80mm f/1.7 R WR. A wide aperture gathers far more light than a slow zoom. For more on this, see primes or zooms on my lenses page, and check the full Fujifilm GFX 50S II page for every lens that fits.

Written by Claude from this site's pages.

From these pages