Skybox player's theatre screen IRL is about one inch wide. Through binocular trickery with foreground and background elements it appears "virtually" to be much larger. How much larger primarily depends on the user's optical and mental processing.
One can actually convince themselves to overcome the trickery and see it for what it is (about 1 inch wide and about one inch from their eyes) or they can accept the lie. 🙂 Red Pill, Blue Pill?
If you blue pill it, there is some math behind it but it's only estimation - as everyone's eyes and brains differ somewhat. Your own estimation will probably be the most accurate.
