RawTerapee 16Bit & 32Bit Floating export suddenly creating washed out thumbnails

Software RawTherapee
1

I use Window 11. Canon R6 (CR3 RAW files). I want the metadata from them, so I convert them
to Adobe DNGs. (Compatibility camera Raw 14 or later.)
Then I edit these DNGs in RawTherapee.
I’ve been doing it this way for a year or two, and exporting/saving them ok.
Suddenly, when I save in 16 Bit or 32 Bit FLOATING TIFFS the thumbnails look washed out in W11 file explorer. But if I export in 16 Bit TIFF (non Floating) the thumbnails are OK. However, the washed out ones then open OK in GIMP, but are washed out if I open them in W11 Photos viewer.
I updated ACR recently, but changed the settings back to camera Raw 14. I also uninstalled RawTherapee, plus all the folders, (cache,profilesetc) from the RT folder and reinstalled it. But still get washed out W11 thumbnails.
Anyone got an idea what’s going on here?

2

This is not RT’s problem, and not sudden. The same would happen if you export from darktable or GIMP… It looks like Windows (and it’s apps) assume a linear colour profile (or no colour profile) when they run into floating point data.

3

Ah. Thanks kmilos. That’s interesting. I read somewhere to use 32-bit floating Tiffs (RawPedia ??) and recently changed to saving them as such. I’ll go back to 16-bit Int. I’m happy it wasn’t me changing some setting or other that I wasn’t aware of.

4

That was not to say you shouldn’t use floating point - that depends on your needs only - just don’t mind what Windows shows.

5

Thanks.

6

I just downloaded the 5.1 rc1 and exported a file to 32bit floating tiff… as you say the thumbs were washed out but in Win11 viewer it opens for a fraction of a second washed out and then its correct…

In Irfanview it is washed out and in XNview its better but not displayed correctly with areas that look gamut challenged…