More info can be found here : The histograms
Clic on the pic for a larger size
Displaying an RGB and Luminance Histogram inside the RAW tab allows to avoid switching continuously between the RAW tab and the RGB tab just to look at the RGB/Luminance histogram. Note: The displayed RGB/Luminance histogram is based on the part of the pic that is displayed at the screen. This has an advantage over the native RGB/Luminance histogram of DPP because DPP displays its histogram for all the pic no matter if you have define a crop area or not. With this new histogram you can see the histogram just for the crop area (or the area you have zoom in). At the opposite if you want a very precise histogram you have to calibrate your screen.
Start the Edit Image Window (select your images in the main window and then press Ctrl + right Arrow).
Clic on the Show RGB checkbox to show/hide the new RGB histogram.
Clic on the L checkbox to choose between the RGB and Luminance histogram.
Clic on the R, G, B chekboxes to show/hide the corresponding channel.
SHIFT-Clic or CTRL-Clic or ALT-Clic on the R, G, B chekboxes to display the corresponding channel alone or with other channels.
Clic on the 2 checkboxes O and U to show/hide Overexposure/Underexposure alerts.
Drag and drop the small squares at the left and at the right of the histogram to change respectively the black point and the white point in the input level.
Drag and drop the small squares at the bottom and at the top of the histogram to change respectively the black point and the white point in the output level.
Clic on the small arrows to change the black/white points with a high precision. Each clic moves the point by 1 unit.
2 thick bars have been added at the left and at the right of the RGB histogram. These bars duplicate respectively the levels 0 and 255 of the histogram. They allow a better visibility when clipping occurs.