SUPPORT
Your camera's warranty, honestly
Huginn connects to your Fujifilm camera over USB-C and Bluetooth using the same picture-transfer protocol the camera already speaks. Fujifilm does not license this kind of connection to small developers, and has told at least one developer that connecting a camera to unofficial software may void its warranty. We are in the same position as every other third-party camera app, so you should assume the same could be said of Huginn.
What Huginn does, and never does
Huginn writes film-simulation settings into the camera's own custom-settings slots, the same C1 to C7 your camera exposes in its menus, plus the movie-mode equivalents. When it finishes, it tells you which slots it wrote and which it left alone.
Huginn never touches firmware. It never writes outside the documented settings areas. It never flashes anything, and there is no code path in the app that could. The settings it writes are the same ones you could enter by hand on the body, and you can overwrite or clear them from the camera's own menus at any time.
Huginn never touches firmware. It never writes outside the documented settings areas. It never flashes anything, and there is no code path in the app that could. The settings it writes are the same ones you could enter by hand on the body, and you can overwrite or clear them from the camera's own menus at any time.
What our own testing found
On our own camera, we compared the body's full stored state before and after connecting: connecting left no marker, no counter, and no record of the connection. The only stored change was the ordinary Bluetooth pairing record, which Fujifilm's own app creates identically. That is our measurement on our hardware, not a statement of Fujifilm's policy, and we will not tell you how to read your own warranty.
Where that leaves you
If your camera is under warranty and that matters to you, the cautious reading is to wait. If you connect, know exactly what Huginn will do: write the same settings you could enter by hand, into the slots made for them, and report what it did. That is the whole of it.