Writes the script — dialogue, scene descriptions, story structure. Everything flows from the page, before the camera rolls.
The screenwriter sits at the beginning of the chain — and this is both a blessing and a burden. They don't just write down a story, but develop a technical document that pulls directors, producers, actors, and cinematographers like you in the same direction. A good screenplay is the blueprint for everyone who stands in front of or behind the camera. Without a solid structure, clear scene sequences, and authentic dialogue, even the best image composition becomes an expensive repair of problems that should never have arisen.
In practice, you immediately notice whether a screenplay comes from someone who understands film language. An experienced writer crafts scenes that are shootable — they know the limits of logistics, implicitly plan for continuity, and keep visual possibilities obvious. Bad screenplays are full of descriptions that only work in the literary mind, or dialogues that no actor wants to say. The writer must understand that a reaction on a face can sometimes say more than three pages of monologue. At the same time, the screenwriter bears full responsibility for the emotional architecture — whether a scene slowly builds or hits with full force is decided here, not during shooting.
The collaboration between screenplay and direction is often fragile. The director will interpret the script, change scenes, cut, and rewrite. The professional writer accepts this — they have laid their foundation, they cannot control more. Some writers are present on set (especially in the English-speaking system), some are not. For you as a DoP, it's relevant: the screenplay is your first orientation for light, movement, and image rhythm. If you can discuss it with the writer early on — all the better. Their intention for a scene can be subtle: a character who feels lost needs different framing than one who has control.
The role of the screenwriter has become increasingly fluid in modern productions. In smaller projects, the director writes themselves. In large studio films, there are writing teams, rewrites, and adjustments during production. The screenplay is not a sacred document — it is a living blueprint that evolves with each discipline, as long as the basic structure remains stable.