I noticed something very weird. When I take a photo of a very bright area like the sun with my Panasonic G9 on ISO 100, there’s a strange pink thing in the sun. Here’s a sample Raw:
http://jpolak.org/downloads/PANA9074.RW2
It doesn’t happen at base ISO 200, only with the extended ISO 100 value. Here is a screenshot in darktable:
This has never happened with any other ISO in the “real” ISO range.
Do you have highlight reconstruction on?
Wow, fast reply! Thanks for the easy fix! It was on, but if I just decrease the threshhold a little, the purple stuff goes away. Nice!
I vaguely recall something about variable black levels… Not sure if its the g9 or another model. A search of the forums might reveal.more to you 
It’s the white level, if I’m not mistaken. But yes, in some cameras it change depending on the ISO.
@JasonTheBirder You should report it on GitHub, so it can be fixed.
Following up on @Donatzsky you might want to check what raw white value DT uses and what is reported in the exif data…that has often in the past shown where the disconnect is…
