ISO-based denoise presets useless for iso-invariant cameras – #8 by g-man – darktable

I don’t get what is useless about an iso preset ?

Iso invariant means that you can freely choose between shooting iso 1600 at ‘correct exposure ‘, or iso 100 at -4ev and raising exposure in post.

It means the shadows are clean enough (AT BASE ISO!!!) to raise in post vs using higher iso in the field (and in doing so saving more highlights ).

This all has nothing to do with how much noise is generated (and profiled ) at certain ISOs?

A profile for iso 100 will try to remove just the noise floor, nothing more . If you leave exposure as shot or raise it with 4ev , doesn’t change the noise added at that specific ISO , right ?

Maybe a profile is a bit too heavy handed in the shadows (which you want to raise to not be shadows anymore ) , but there is a shadow bias slider for that… And it basically means the iso profile is a bit too crude.

Tl:dr, iso invariant sensor has nothing to do with profiling how much noise it generates at certain ISOs.