🎬 Starlit Attic Cinema Retreat: Projector Optics, Sabine Room Acoustics, Telescope Resolution and a Planet Orrery

Run a star-ceilinged attic cinema: set projector throw, lumens and screen gain against ambient light, tame the room's RT60 with Sabine, Eyring and ray tracing, split double stars with Airy diffraction and seeing, and track the shelf planets on a Kepler orrery while hosting guests.