Nikon 25338 User Manual - Page 146

Chapter 22 140 slider down, you darken the lightest luminosity level in the image. These two sliders are often used if the darkest and lightest colors should not be black and white. SHOW BEFORE / AFTER HISTOGRAM BUTTON This button toggles back and forth between before and after histograms. The before histogram always remains the same and represents the histogram before any adjustments have been made on the image by the current channel. The after histogram always updates itself based on the changes made by the Levels & Curves editor. WHITE POINT DROPPER Clicking on this button will change the mouse cursor into a White Point Dropper cursor. By then clicking on your image, you will set the White Point Sliders for all three color channels to the value of the color selected by the White Point Dropper. Use this tool along with the Double-Threshold command from the Photo Info Palette to identify the lightest value in the image that you want to be white. The White Point Dropper will affect both the tonality of the active image as well as the color balance. For more information on the Double-Threshold feature, please see page 100. Adjust Menu AUTO CONTRAST BUTTON Click on this button to automatically distribute the colors of each individual channel by modifying the white and black points within each individual channel. Ctrl (Windows) or Option (Mac OS) click to affect the current channel only. Capture NX automatically selects white and black points that exclude a certain percentage of the brightest and darkest pixels in the image, steepening curves for enhanced contrast. The exact percentage of pixels excluded can be specified in the Preferences dialog. By default, 0.5% of the brightest and darkest pixels are excluded, producing a curve that makes optimal use of the output tone range, while preserving details in shadows and highlights. Hint: For even more control over setting the white point in your image, try using the White Control Point from the Control Point Menu. For more information on White Control Points, please see page 165. NEUTRAL POINT DROPPER Clicking on this button will change the mouse cursor into a Neutral Point Dropper cursor. When you click on your image, Capture NX will attempt to make the selected color neutral without affecting the tonal values by setting the mid point sliders for all three color channels. The Neutral Point Dropper attempts to affect only the color balance of the image; however, if the targeted color contains a significant amount color, this feature will affect the tonality of the image. Hint: For even more control over