The Gorman conversion method is a Lab L channel based method. It combines L channel conversion with masked solid layer toning and high pass filter sharpening. Because it ignores color information, this method works better on images that have little color to begin with.
Steps in Photoshop
Lab L Channel conversion
- Select to convert the image to Lab mode.
- Go to the Channel palette and select the Lightness channel
- Select to discard the “a” and “b” channels.
- While holding the Ctrl key click on the Gray channel. This will select the highlights.
- Select to select the shadows.
- With the shadows selected select to convert back to RGB.
Solid Color Layer toning
- Go to the Layers Palette.
- Create a new Solid Color layer.
- Select a color from the color chooser.
- Change the Blending Mode of the solid color layer to Multiply
High Pass Filter sharpening
- Hit to create a new merged layer.
- Change the blending mode of the new layer to Overlay. Set opacity to 20%.
- Set the radius to 50 pixels.
You can pick a different color for the fill layer for your toning.
Named after photographer Greg Gorman, the Gorman method was developed before Photoshop added black and white conversion layers in CS3. Although it’s an older method, it remains popular due to the dramatic contrast it can create. However, there are two drawbacks with Gorman. First, it can’t take advantage of color information to push contrast in a specific direction. For example, you can’t use Gorman to push the sky towards black or trees toward white like you can with the regular black and white conversion layer. Second, images that are already high-contrast won’t benefit from the solid color layer. In fact, it may cause more problems by creating blocked shadows.