The Gradient and Channel Mixer Black and White Conversion Process One of the many possible Black and White conversion methods in Adobe Photoshop involves the use of a Gradient and a Channel Mixer adjustment This method is really simple to apply using the steps outlined below and produces results that are far superior to a simple desaturate or Greyscale method. Again, starting with the obvious; open up an image in Adobe Photoshop that you wish to convert to Black and White.

Photo 1. Goodman

Make sure that you have Black as your foreground colour and White as your background color. Simplest way to do this is to press the D shortcut key. (Another simple shortcut key to remember is X which simply swaps the foreground and background colours around. Now apply a Gradient Map by selecting either the Image | Adjustments | Gradient Map... menu item, or by clicking on the Adjustments icon in the Layers palette and choosing Gradient Map. Simply press OK on that dialogue (see Figure 1.) and you will instantly have a black-and-white image that is oftentimes better than your simple desaturated or greyscale image. Alternatively by clicking on the Gradient Used for Grayscale Mapping gradient icon you can edit the gradient (see Figure 2.) to adjust the levels of black and white thereby adjusting the contrast if so desired. Personally for me however I usually just leave the defaults as it works out quite nicely.

Photo 2. Thirst

  
Figure 1.  Figure 2.

We now need to apply some Channel Mixer settings to our image to introduce some tonality and establish the correct balance between lights and darks and all the levels of gray in between. To get to the Channel Mixer dialogue (see Figure 3.) you can simply add a new Adjustment Layer by clicking on the icon in the Layers palette and choosing Channel Mixer.... You can also add this Adjustment layer by using the menu, but you must first make sure that you have the Background layer selected in your layers palette. If you have the Gradient Map selected, as per the previous step then the menu-item in the Image | Adjustments | Channel Mixer... menu is not available. When the dialogue opens up the first step that you must undertake is to select the Monochrome check-box at the bottom of the dialogue otherwise any changes you make will look really weird. We are after all working in monochrome, so hopefully this setting makes sense. Thereafter, you can apply the following rule of thumb: Constant: -8% Red Channel: 75% Adjust the Green Channel upwards until your image starts to look weird and then bring it back a percentage or two Do exactly the same with the Blue Channel The Adjustments of the Green and Blue channel are done entirely to taste and you will begin to get a feel for what looks good and what doesn't.

Photo 3. Mists of Time

Figure 3.

Finally, you can try one last trick with this method and that is to swap the layer order of the Gradient Map and the Channel Mixer around for varying effects. Sometimes your image looks better with the Gradient Map as the top layer, other times the Channel Mixer layer is better suited on top.
Layers can easily be moved around in Photoshop. A simple way of doing this is to drag the layers up or down in the Layers palette with the mouse. Alternatively you can use the keyboard shortcuts: Ctrl+[ to send the selected layer to the back.
You can of course as always alter the Opacity setting of any one of the layers to minimise the effects of your Adjustment. Try it for yourself and see the results.
I hope that you have enjoyed this 2nd tutorial in the series and that you find new pleasure in your black-and-white conversions to produce images with greater contrast and a nicely balanced tone across the range.