CUT TO: questions

I was reading the iconic shower scene from Psycho (posted as a "Great Scene" of the day at, again, Go Into the Story) and seeing Joseph Stefano's direction in the script as to how it should be filmed... I was stricken. Where, in film, does the writer end and director begin?

Maybe to some it seems obvious, but coming from a theater background it is a little strange to see all the "stage directions" on the page. Not so much the action, I very much understand the inclusion of that, but more so the "shots" it describes. It doesn't only describe what is going on, but how we see it which is what surprises/confuses me a little. This is the iconic Hitchcock film... how much of that scene is Hitchcock, and how much of it is Stefano?

Much of the specifics, angles and the like, is something I'd expect the director do. Is it because it's a shooting script and it is after the director and writer have collaborated? In that case my reading of the shooting script in whole won't answer my question. Is the writer responsible for how the viewer is to eventually see his action in such a way? In part, of course, the way it's filmed would effect the story greatly, but still, coming from theater it's something I'd expect the director to have the greater responsibility for. Also, is what the writer describes as far as scenes and editing - Cut to, reverse angle, the camera moves away - something one expects to be changed by other parties eventually and the writer does mostly in the spirit of conveying better the tone of the story? In that case, it would be the writer's attempt at communication to parties involved, so when/if it does get changed, they are better able to keep the writer's vision in tact (if they wish to be so respectful). I understand that these bits are often likely to be added once the script is bought and not usually included to such a degree in one's spec script, so perhaps the idea of it being after collaboration makes sense (but so does the expectation of a director throwing it out). Or does the writer tend to only start listing such specifics in a particularly pivotal scene? Coming to think of it, the screenplays I've read don't constantly describe the angles, it's more a "sometimes" thing, so this may yet be the answer.

Maybe they're all right and it's all circumstantial. I'm sure it is, regardless, to a point. But I'm also sure there must be a more precise answer than "it depends."

I don't have the answers to these questions yet but I thought it important to include them up here so as to remember them in the future.

I'll try to remember and post an update when I eventually discover the answer.

The scene also had me questioning something else re: playwriting vs. screenwriting, but I'll post it separately. Long posts can be daunting to a reader.