First: http://www.projectorcentral.com/pdf/projector_manual_1990.pdf Looks like page 14 of the manual (15 of the pdf) in the image menu, you want to adjust the 'mirror' settings. At least, that's my guess. This is clearly a older model projector and the 4:3 native aspect ratio and [censored] poor contrast are indicators of just how much it is designed for use in a board room, not a home theater. Hopefully it was free to you - or nearly free, as it is completly wrong for home theater. On the other hand, it's a good place to start. Of course you will need the lens somewhere from 13 to 17 feet from the screen to get the image to fill the space.