Working with the Black & White Controls

You use the Black & White adjustment controls when you want more control over converting your image from color to black and white than simply desaturating it gives you. The Black & White adjustment controls allow you to adjust tonal relationships and contrast in an image by adjusting the red, green, and blue channels independently. The effects of a Black & White adjustment are similar to the effects of attaching a color filter to a camera lens and shooting black-and-white film.

Figure. Image before and after a Black & White adjustment.

The key to the successful use of the Black & White adjustment controls is to experiment with changing values for the Red, Green, and Blue parameters until you are satisfied with the effect on the image.

Note: A good rule of thumb is to keep the total percentage of the red, green, and blue channels at or below 100 percent to prevent you from blowing out the highlights in your image.

To convert a color image to black and white using the Black & White controls
  1. Select an image.

  2. If the Black & White controls are not shown in the Adjustments inspector or the Adjustments pane of the Inspector HUD, choose Black & White from the Adjustments pop-up menu (or press Control-M).

  3. Adjust the mixture of red, green, and blue channels by doing one of the following:

    • Drag a color slider to the left to decrease the color’s percentage in the color mix, or drag the slider to the right to increase the percentage.

    • Click the left or right arrows in the value sliders to modify the percentages by single increments, or drag in the value fields.

      The left arrows decrease the percentage, and the right arrows increase it.

    • Double-click the number in a value slider, then enter a value from –100% to 200% and press Return.

      Figure. Controls in the Black & White area of the Adjustments inspector.

The tonal and contrast values in your black-and-white image are set.

You can also brush the Black & White adjustment on selected parts of an image. For more information, see Making Brushed Adjustments.