Sony A7R III Converted to Monochrome Visible Light 42.4 Megapixel Back Side Illuminated (BSI) sensor.
Monochrome camera is 3X more sensitive to visible light after conversion.
The Sony A7R III converted to monochrome gains tremendous spatial and contrast resolution compared to its color version. With camera sensors, there is only a certain amount of information that can be passed and when that information includes color detail, you have to reduce the contrast and spatial detail. That's why converting a color picture in post to monochrome will never give you the same results a true monochrome picture.
Here is an example shot with camera resting on a surface (no tripod) using a Sony 85mm F1.8 lens at ISO 400 and 1/15 second shutter.
Now, let's start zooming in to the picture - this is from the same picture - not multiple pictures.
Here you can see an inverted image of the interior of the workshop. There are fluorescent lights on the ceiling, garage door windows on the right and various other stuff in the garage.