FujiFilm GFX100S: Multi-Shot High-Res Mode Examined Critically — Can it Be Used Outdoors and How Good is It?
re: Multi-Shot High Resolution Mode
In multi-shot high-resolution mode, the Fujifilm GFX100S takes 16 images with the sensor shifted whole and half pixels, writing them all to the camera card. On the computer, FUJIFILM Pixel Shift Combiner assembles those 16 images into a single DNG file with 4X the pixels (2x linearly) eg 400 megapixels for an image of 23264 x 17448.
This page looks at image quality (or lack thereof) accruing from the Fujifilm GFX100S multi-shot high-resolution mode.
FujiFilm GFX100S: Multi-Shot High-Res Mode Examined Critically
Includes images at 200 megapixels from f/5.6, f/8, f/11 from single-shot and multi-shot, plus matched crops and extensive analysis.

Fujifilm GFX100S + Fujifilm GF 35-70mm f/4.5-5.6 WR @ 53.6mm equiv (65.2mm)
RAW: distortion corrected, vignetting corrected, +20 Whites, +10 Clarity, diffraction mitigating sharpening, SmartSharpen{35,0.8,20,0}
[low-res image for bot]