The DSC Labs Backfocus Standard Focus Pattern Chart (21.3x13") is designed for calibrating the focus on your video camera. Many video professionals consider calibration charts a necessity for optimizing camera performance and the production value of images. This chart has been designed with that philosophy in mind and works equally well in engineering or production work. This model features an exceedingly high dynamic range with brilliant white and dense black shades. Unique bow-tie stars and demi-stars are also included to help set critical center and edge focus parameters.