Ivan Tsyba wrote: > But target curve is offsetted by default, so why ideal black system 50% > input is used instead of offsetted? I'm not quite sure what you mean. The typical gamma target is for an ideal system that has a zero black. Real systems aren't like this, so simply scaling and offsetting the curve for the real black raises the level, which can lead to a poor match against something with the same gamma and a lower black level. By making the 50% point match the ideal system, then the overall contrast and look will be consistent with the ideal system target, irrespective of the actual black level. Graeme Gill.