How Good is the Sony A7R IV for Monochrome vs the Leica M10 Monochrom and/or Nikon D850 Monochrome?
Several readers had asked whether a Fujifilm GFX100 (Fujifilm GFX100S has the same sensor) might vie with the Leica M10 Monochrom for black and white images—I explored that a few days ago.
So I thought that it made sense to do the same thing for the Sony A7R IV.
This is not a head-head-head shootout, but it offers a useful perspective.
Sony A7R IV: Monochrome Conversions, Perspective
Includes four examples at up to full camera resolution.
If only Sony would release a Sony A7R IV Monochrome free of PDAF pixels, it would seal the deal on making Sony an ideal choice for the want-it-all landscape photographer. Having one system and one set of lenses with both color and monochrome camera bodies would be unbeatable for landscape and similar.

Sony A7R IV + Sigma FE 105mm f/1.4 DG HSM Art
ENV: Alabama Hills, altitude 5100 ft / 1554 m, 55°F / 12°C
RAW: LACA corrected, vignetting corrected, push 0.17 stops, +100 Shadows, -100 Highlights, +50 Whites, +88 Blacks, Color Luminance {Blues -76, Purples +100}, +40 Dehaze, +30 Clarity, Chroma NR {40,20,50}, USM {20,50,0}
ACR BW07
[low-res image for bot]
Toggle to compare monochrome to color.

Sony A7R IV + Sigma FE 85mm f/1.4 DG DN Art
RAW: LACA corrected, pull 0.27 stops, +30 Shadows, +30 Whites, +15 Clarity, USM {8,50,0}
[low-res image for bot]

Sony A7R IV + Sigma FE 105mm f/1.4 DG HSM Art
ENV: Alabama Hills, altitude 5200 ft / 1585 m, 30°F / -1°C
RAW: LACA corrected, vignetting corrected, push 1.1 stops, +40 Whites, +15 Clarity
[low-res image for bot]

Sony A7R IV + Voigtlander FE APO-Lanthar 50mm f/2 Aspherical
RAW: LACA corrected, push 1.95 stops, +100 Shadows, -93 Highlights, +50 Whites, +15 Clarity, Chroma NR {10}, USM {10,50,0}
[low-res image for bot]