In recent years, much attention has been paid to a projection type display apparatus using a plurality of light sources, as projection type video equipment capable of large screen display. However, in an optical system using a plurality of light sources, devices are designed so that uniform lighting can be provided assuming only the use of all the light sources. Thus, the uniformity of brightness within a display screen may be degraded if not all of the plurality of light sources are used.A light apparatus includes a plurality of lamp unit sections, a synthetic mirror section that reflects and synthesizes lights generated by all or some of the plurality of lamp unit sections and, and a synthetic mirror section adjusting mechanism that holds the synthetic mirror section so that its position can be changed so as to adjust the reflecting optical paths of the reflected lights.