Ive used the spherical mirror in a small dome, what resolution projector do I need for a large fixed planetarium?
An interesting question. All other things being equal, the size of the dome doesn’t matter. By that I mean, the perceived resolution on the dome doesn’t change as the size of the dome changes. The perceived resolution is the angle a pixel subtends at the eye, in a small dome the pixels are smaller but closer to the eye, in a large dome the pixels are larger but further away … the angle the pixel subtends at the eye is the same. In reality, for a given projector resolution the effect on a large planetarium dome will be better than in a small inflatable (say) dome because in general the dome surface for the planetarium dome will be better.
