A projector includes an OSD image generation section that generates an OSD image, an OSD processor that generates a combined image in which the OSD image is superimposed on an input image, a light source section that outputs a light flux, a light modulator that modulates the light flux in accordance with the combined image to produce image light, a projection system that projects the image light, and a placement detector that detects whether an additional lens that changes the ratio between values in intersecting two direction in the image light has been inserted into the optical path of the projection system, and when the placement detector detects that the additional lens has been inserted, the OSD image generation section generates the OSD image in accordance with the inserted additional lens.