7. Advanced7.8.5.4 Black levelOverview• Introduction• Internal black level• Beta planes7.8.5.4.1 IntroductionBrightness uniformityIn a multi channel system the brightness can vary over the different channels/projectors. The brightness level can be matched using:1. CLO: in this case the light power is matched over the different projectors, see CLO in the Lamps section2. Black level : this will act on the brightness of the “black” color of the image part situated outside the soft edge zones.Internal black level versus Beta PlanesIn the same way as for the soft edge adjustment (Internal vs Alpha planes) this black level adjustment can be fixed internally byusing a dialog box or externally by uploading a user defined Beta plane. This beta plane will contain the values for the brightnessoffset to be applied to the image.Both methods will allow to compensate for the typical double brightness phenomenon in the soft edge zones by increasing thebrightness of the rest of the image.channel 1 channel 1Overlap zone (double brightness)channel 1&2pulled upImage 7-137Black level : double brightness compensationIt is worth noting however, that (internal) black level (via the dialog box) is to be used for simple linear softedge zones (like in the illustration above). Curved soft edge zone should be done using (external) beta planes.R59770330 SIM 7QP SERIES 08/12/2014 123
