Nikon 4 user manual Master Lightness Channel, Show Histogram button

Image Adjustment

The Master Lightness Channel

Although it affects brightness rather than color, editing luminosity has a similar effect to edit- ing the master curve in the Curves palette.

Show Histogram button

White-point output

level slider					Auto Contrast button
					Luminosity curve
Black-point output					Histogram
level slider
Black-point	Mid-point		White-point
input slider		slider		input slider

Luminosity curve: Maps luminosity in the original image (input) to the luminosity of the image after editing (output). Any portion of the curve can be edited as described in “Curves” ( 48); steepening the curve increases the difference between light and dark areas of the image, increasing contrast.

Histogram: Shows the distribution of pixels of different luminosities in the input. The hori- zontal axis corresponds to luminosity (in the range 0–255), the vertical axis to the number of pixels.

Output level sliders: Choose the maximum (white point) and minimum (black point) values for output.

Input level sliders: Choose the maximum (white point) and minimum (black point) input levels.

Mid-point slider: Set the mid-point (gamma value). Moving the mid-point alters the bright- ness of mid-tones while preserving detail in highlights and shadows.

Show Histogram button: Click to view the luminosity distribution for the final image. Click again to view the input luminosity distribution.

Auto Contrast button: Set the maximum and minimum input levels to exclude values for 0.5% of the brightest and darkest pixels in the crop. The percentage of pixels excluded can be ad- justed in the Advanced Color tab in the Preferences dialog.

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