Digital or film photography camera — runs parallel to principal photography for press assets and set documentation. Operated independently from crew.
On set, it's constantly running in the background — the still camera documents while the main camera records the take. A separate device, usually operated by a dedicated photographer, that works parallel to the film production and functions completely independently of the cutting list and shooting schedule. The shots later serve as press photos for festivals, cinemas, and studios, for behind-the-scenes content, and for internal set documentation. Without still photos, there's no decent press kit — and that's precisely what you notice later when post-production begins and nobody has usable images for the distribution company.
Practically, this makes a difference: While the film camera has its focal length, angle, and movement, the still photographer positions themselves flexibly in space, capturing details the film camera doesn't see, waiting for the right moment between takes. Digital is the standard today — a high-quality DSLR or mirrorless camera with at least 24 megapixels — because the image quality must hold up later in print and online media. Some sets still work with medium format if the budget allows and the press photos are intended to be very large. Analog material has become rare, but it can still make sense for certain festival contexts (Super 8, Polaroid aesthetic).
The still photographer needs a different eye than the DoP. While the cinematographer plans the composition for 24 frames per second, the still photographer works with individual, perfect moments. Good light for the film camera isn't automatically good light for still photos — they often have to position their equipment so they don't get in the film camera's light cone or disturb the sound. Flash use is taboo during takes, but additional lighting between shots can be very useful for creating impactful images. Most importantly: they document the actors in their roles, the set dressing, the set atmosphere — not as works of art, but as usable material.
For the DP or director: You don't just place the still camera next to the monitor. It needs its own space, freedom of movement, and clear agreements on when photography is possible and when it isn't. Good material at the end of a shooting day can make the difference between a presentable press kit and a useless collection of bad snapshots.