CompuServe Messages

Video Black & SuperBlack

    08-Jun-94 05:00:22
Sb: #105764-Video Black & SuperBlack
Fm: Paul Minni 71053,3516
To: MicroCAD Digital Imaging 76050,212
<<< The problem we are having is getting the black levels to be 7.5 IRE and not 0.0 IRE. …it always renders it at a 0.0 IRE black level whether we turn on Superblack or not. We are looking at the signal through a waveform monitor to be sure. >>> Since you are using an AT Vista, which requires an outboard encoder for NTSC video, check your video encoder settings, it may have a switch or pot labeled SETUP or PEDESTAL or BLACK LEVEL. You can adjust this control so that 0 RGB = 7.5 IRE (or it may be just an ON/OFF switch). If your encoder does not have this control then I'd use Gary's idea of making your black value brighter. This way if you need 0 black for keying you don't have to mess with your video hardware. Paul