Essentially it's a camera that allows anyone to "see the impossible" and capture it on film. One can capture spirits on the film, but it can also let someone capture an image of what an area used to look like. For example, if taking a picture of an old battlefield. Despite it being clear to the naked eye, the picture might show the battlefield full of weapons, bodies, or other signs of battle.
If there's a locked door, a picture of it might show an image of the area the key is, or something that needs to be destroyed or collected before the door will open.
(This isn't a guaranteed thing or something that always happens, it's sort of "as needed" and something I'd always ask about first if there's something she could pick up).
It can harm spirits/supernatural creatures whose picture is taken by the camera. The film has exorcism power with stronger film meaning stronger attacks, but they are finite amounts of those films. The lowest exorcism film is automatically part of the camera and unlimited and Miu would be bringing no additional film in with her.
Re: Clarification
She'll be bringing her mother's hairpin and her Camera Obscura. ( https://wiki.thelostvillage.net/index.php/Camera_Obscura )
Essentially it's a camera that allows anyone to "see the impossible" and capture it on film. One can capture spirits on the film, but it can also let someone capture an image of what an area used to look like. For example, if taking a picture of an old battlefield. Despite it being clear to the naked eye, the picture might show the battlefield full of weapons, bodies, or other signs of battle.
If there's a locked door, a picture of it might show an image of the area the key is, or something that needs to be destroyed or collected before the door will open.
(This isn't a guaranteed thing or something that always happens, it's sort of "as needed" and something I'd always ask about first if there's something she could pick up).
It can harm spirits/supernatural creatures whose picture is taken by the camera. The film has exorcism power with stronger film meaning stronger attacks, but they are finite amounts of those films. The lowest exorcism film is automatically part of the camera and unlimited and Miu would be bringing no additional film in with her.