you may thought i was stupid to ask this question because the parameters tell the camera how to convert raw data into jpg images (shooting in jpg mode)
however, ive recently learned that when the camera displays the histogram of an image, it displays the histogram of the jpg result, not the raw data. so, the way we set the parameters will affect the way the histograms displayed. and i have no idea how to set these parameters so that the histogram will display most accurately possible?? (for a 20D and for a 1DsII to be specific, since the 20D displays 1 histogram and the 1DsII displays histograms for separate channels)