Field

Each full picture is divided into 2 sequential fields, each of which contains half the scanning lines of the table. A field containing the odd scan lines, and the other field lines scan pairs.

The maximum luminance peak for a projector is typically along the direction of its lens's optical axis and it diminishes with a Gauss-like function orthogonal to this direction. This results in a non-constant luminance distribution within each projector's field of view such that the image appears brighter in the middle and darker towards its edges. Equalizing luminance non-uniformity. Some expensive projectors can be equipped with specialized hardware that equalizes the luminance non-uniformity. Alternative solutions are to use an external custom-built light mask installed in front of the lens or advanced software-based image correction.