To provide a support capable of easily composing a projection system.

A support 4 comprises: a first support member 5 to which a first projector 2U is fixed; a second support member 6 to which a second projector 2D is fixed; and moving mechanism 7 connecting the first and second support members 5 and 6 and configured to move the first and second support members 5 and 6 relative to each other. The first and second support members 5 and 6 are relatively moved, so that the moving mechanism 7 positions the first projector 2U to a first position in which at least part of a top face 21A of the second projector 2D is covered or a second position in which the top face 21A of the second projector 2D is opened.