Nikon 9235 Reference Manual - Page 136

Sample Point Size This setting determines the size of the area sampled when displaying the color value for the pixel under the cursor in the information window, or when the white-point, gray-point, and black-point tools are used in the Curves palette. You can select a sample sizes of 1 × 1, 3 × 3, and 5 × 5 pixels. When the sample size is set to 3 × 3 or 5 × 5 pixels, the average for the pixels sampled is used. Choosing a large sample size reduces precision, but also minimizes the effects of noise; choosing a small sample size has the opposite effect. Scan Window Settings The Preview Tab Using the Preview tab, you can select the settings that will automatically be applied to images when the Preview button is clicked. Auto Contrast Calculations A further option in the Color sheet allows you to specify how auto contrast operations in the Curves and LCH Editor palettes calculate the input values for the white point and black point. By default, the white point is set to a value that excludes 0.5% of the brightest pixels in the current crop, the black point to a value that excludes 0.5% of the darkest pixels in the crop. This produces an optimal dynamic range, with minimum loss of detail in shadows and highlights. To preserve detail at the expense of dynamic range, lower the "excluded" value for auto contrast (a value of zero will set the black and white point respectively to the darkest and brightest pixel in the crop). To increase the dynamic range at the expense of detail, raise the "excluded" value. Reference: Preferences 135