What causes the image to keystone?

Keystoning occurs when the projector is positioned above or below the center of the screen surface. This causes the distance to the top of the displayed image to be much greater than the distance to the bottom of the image, or vice versa. The result is that the image is either wider at the top than at the bottom or wider at the bottom than at the top. In either case, the correction is the same.

How is keystoning corrected?

Using the on-screen display (OSD) Keystone option, Gateway projectors can electronically compensate for keystoning and are able to display a rectangular image.

Note: Do not use the OSD Keystone correction when displaying images of spreadsheets and full-text screens. Doing so causes the displayed image to have a zebra stripe-type appearance.