Fujifilm GFX100S: Unacceptable Image Quality for Monochrome Images — Horizontal White Stripes
re: Reader Comment: Fujifilm GFX100S and Captures for Monochrome
re: PDAF banding and striping pattern noise
re: Fujifilm GFX100S Horizontal White Stripes: the Futility of Using GFX100S for Monochrome Landscape Images — Total Image Quality FAIL
Bad news for monochrome shooters hoping to shoot the Fujifilm GFX100S as a substitute for a monochrome-sensor camera by beating 'em with more pixels... the horizontal white stripes seen in the Fujifilm GFX100 have not been fixed with the Fujifilm GFX100S.
Many people have claimed the issue is fixed. But I reproduced the problem with the very first frame I shot to test for it. The issue is thus not only present with the GFX100S but almost certainly not fixed in the Fujifilm GFX100, which has an identical sensor.
Fujifilm GFX100S: Horizontal White Stripes with Monochrome Images aka PDAF Banding
I discuss one other curiousity and where the striping is found.
UPDATE: I confirmed that under identical conditions, the Sony A1 does not show striping whereas the Fujfilm GFX100S has it in spades.

Fujifilm GFX100S + Fujifilm GF 30mm f/3.5 R WR @ 24.7mm equiv (30mm) + polarizer Zeiss
RAW: push 0.35 stops, +20 Whites, +15 Clarity
14-bit
[low-res image for bot]