Getting HEIC & RAW thumbnails in Gnome

For HEIC:

$ sudo dnf install libheif-tools

Source: https://www.reddit.com/r/Fedora/comments/14eys74/i_finally_figured_out_how_to_make_heic_thumbnails/

For RAW support:

$ sudo dnf install rawthumbnailer

This automatically had support for CR2 Canon and ORF Olympus files I have. But it was not supporting Fujifilm RAF.

Opening up /usr/share/thumbnailers/raw.thumbnailer I could see that RAF was not included as a recognized mimetype.

Luckily, all it took was adding:

image/x-fuji-raf;

And voila, Gnome began showing thumbnails for RAF!