Am 27.10.2010 15:21, schrieb Anders Torger: > > So if I display an image with RGB color 0,0,0 (black) I would expect it to be > sent to the screen as 0,0,0 and not some non-zero calibrated value,... Assume for instance a display where RGB numbers of 0, 1, 2, 3, ..., 6, 7 all result in a black output on the screen (within measurement tolerances) and only numbers >= 8 result in an output brighter than black. Then it does not matter whether you drive the display with 0 or 3 or 7 - the result you see will always be the same, namely black. In this case, using the RGB value 7 for black, and not 0, has however the advantage of a relatively flat gradient (only a difference of 1) from the RGB value used for black to the first non-black value, while using 0 for black would imply a steep gradient (i.e. a jump from 0 to 8) from black to the first non-black value. Now let's look what for instance may happen if the max. RGB number which gives a black output drift a little bit downwards after the calibrations has been established (say from 7 to 4). Then the big step from 0 to 8 may suddendly become visible as discontinuity/banding, because RGB=8 would then become brighter, due to this drift, while the output for 0 won't change. However, if value 7 is used for black then the same kind of drift would certainly have the effect that "black" is now displayed a little bit brighter, but the step from 7 to 8 (i.e. from "black" to the first non-black) will likely still result just in a small visible difference, avoiding the discontinuity/banding near black. Regards, Gerhard