The LAB Black and White Conversion Process There are many ways of converting standard colour images into Black and White in Adobe Photoshop (and other packages for that matter). Many of them however leave much to be desired in terms of contrast and tonal variation. The method presented in this tutorial uses the LAB color space in Adobe Photoshop to pull-out the grayscale channel. It is by no means the only and only method you should use for your black-and-white photography but if it stands-alone it is certainly a better method than a simple desaturate command. First step is naturally to open up the image that you wish to manipulate into Photoshop (hopefully you had that bit figured out already?)

Photo 1. Laura-Ashley

As an aside, it's usually a good idea to be working on your image in 16-bit mode to achieve the most balanced histogram. If that doesn't make sense to you, look out for future articles pertaining to RAW mode and histograms. Convert the image colour profile into LAB by selecting the following menu item: Image | Mode | Lab Color Navigate to the Channels palette (either by choosing the Channels tab in the Layers | Channels | Path window or selecting the Window | Channels menu item.) Select the Lightness channel or press Ctrl+1 shortcut key.

Photo 2. A Resting Spot

The next step, is to turn the image into Grayscale and the simplest way of doing this is to select the Grayscale color mode by choosing Image | Mode | Grayscale. Be sure to select OK when prompted with the Discard Other Channels prompt. (See Figure 1.)

Figure 1.

Your image probably now appears very light and washed out. We need to add in some contrast and we do that by adding in a Multiply Layer. The Multiply layer in Photoshop is simply a method of telling PS to double the value of each pixel in the layer before it. So in order to achieve this, we must first duplicate the current layer. You are probably still in the Channels palette, so first go back to the Layers palette by either clicking the Layers palette tab, or by navigating to it via Layers or by pressing the shortcut key (F7).
Duplicate the current layer by selecting Layer | Duplicate Layer... or using the keyboard shortcut Ctrl+J.
Change the blending option of your new layer to Multiply. To do this, either change it on the Layers palette (selecting Mutliply) or go to the Layers Blending Options dialogue by choosing the menu Layer | Layer Style | Blending Options.... This menu item brings up a dialogue ( (See Figure 2.) from which you should choose Multiply in the Blend Mode drop-down box.

Figure 2.

Your image probably looks way too dark, but don't worry as that is easily fixed. You simply need to adjust the Opacity setting of this new layer which allows some of the underlying pale layer to show through thereby effectively reducing the 2x effect of the Multiply layer. This will be done entirely to taste in accordance with the image that you are working on (usually anywhere between 30% and 80%). To further enhance the contrast still, you might consider applying an Overlay layer to your image or applying another black-and-white conversion method to this already converted image. For simplicity let's just focus on the Overlay layer, and you can achieve this in a similar method to the Multiply layer that you applied above. Begin by first flattening your existing image, Layer | Flatten Image, duplicate the background layer with Ctrl+J, select the Blending mode to be Overlay and adjust the Opacity setting to your liking, usually between 30% and 50%.

Photo 3. Duality

Well, that is LAB Black and White conversion in a nutshell. I hope you find it simple and easy to use and that it improves your black-and-white processing beyond the simple desaturate command. As I stated up-front, there are many other methods of converting to black-and-white, some of them simpler, some of them better which we will cover in later tutorials. Often I find myself combining methods which can be a useful trick for really bringing out some black-and-white contrast.
I'm going to leave you with a technique for you to try yourself and see what results you can come up with and that is to apply some Dodging and Burning to your black-and-white image. This will really bring out the blacks and enhance the whites even further. The trick to remember is firstly that Dodging brightens your whites and Burning darkens your blacks. Photoshop default percentages MUST be ignored in both instances as they are way too high. Try settings like 2%-8% for a more realistic adjustment.
Play around with it and we'll come back to Dodging and Burning in future as well.