Optoma TS400 User Manual - Page 28

User Controls English ... 28 Management Menu Location Choose the menu location on the display screen. Projection  Front-Desktop The factory default setting.  Rear-Desktop When you select this function, the projector reverses the image so you can project behind a translucent screen.  Front-Ceiling When you select this function, the projector turns the image upside down for ceiling-mounted projection.  Rear-Ceiling When you select this function, the projector reverses and turns the image upside down at same time. You can project from behind a translucent screen with ceiling mounted projection. Signal Type Select signal type RGB or Video sources. Source Lock When this function is turned off, the projector will search for other signals if the current input signal is lost. When this function is turned on, it will search specified connection port. High Altitude Choose "On" to turn on High Altitude mode. Operates the fans at full speed continuously to allow for proper high altitude cooling of the projector.