Converting to Black and White

If you like to shoot black and white you have several options to control the way your image is going to turn out. If you have a digital camera you can always choose to shoot the image as a black and white to begin with, and there are even some cameras that allow you to apply special color effects filters in camera just like you would in the good old film days. In any of these cases you’ll have a black and white image that you can immediately open in Photoshop and apply further adjustments to fine-tune for your taste.

There is also the school of thought that even if you know you want the image to be black and white you still shoot it in color and convert it later. This way you always have both versions just in case you change your mind later and want to keep it a color image. If you like this option or have an existing file that is in color there are several choices in Photoshop to convert it to black and white.

The first options are to convert the file to a straight black and white by using the desaturate command or by converting it to a grayscale image. If you use the grayscale command you can leave it there, which will not allow any color to be put back in, or you can reconvert it to RGB and then be able to add a color tint like a sepia tone for an old fashion look. You can use this method by going to Image > Mode > Grayscale and then if you want to go back to RGB you do the same Image > Mode > RGB color. The second method is to desaturate by going to Image > Adjustments > Desaturate and then if needed you can apply any color tints or contrast adjustments from here. Since both of these methods are changing the original pixels you will want to perform these on a background copy layer so if you don’t like the results you can throw that layer away and start over. Both methods will render similar results with the desaturate method being quicker and easier in the end.

The next two options involve using adjustment layers to do the conversion, which is nice because they won’t permanently alter the file’s pixels. The first layer is the Hue and Saturation and to access this go to Layer > New Adjustment Layer > Hue/Saturation or click on the half circle icon at the bottom of the layers palette and then Hue/Saturation. When you open the layer click the colorize box and you’ll notice that your image will change to a black and white with a tint of color. The hue slider will change the tint while the saturation slider will change how much that tint shows. If you push the slider all the way to the left it will take all color out and leave you with a straight black and white. Sometimes an image may look too cool when converted to black and white so this is a good way to put just a hint of warmth into the picture.

The second layer is the Channel Mixer layer. Using the channel mixer layer allows you to apply varying amounts of red, green, and blue to get an effect like you would if you put a color filter on the front of your lens. You can first get an idea of which color channel works best for your image by going to the channels palette and clicking the different color channels individually. Once you find the one you like, create a channel mixer layer and then move the corresponding color slider to 100%. For example, if you liked the red channel, move the red slider to 100%. If it was green, move the green slider to 100% and so on. You can also move any combination of the three sliders to get the effect you’re looking for. To avoid blowing out the highlights or blocking up the shadows, adjust the sliders so the three percentages equal 100%.

If you have Photoshop CS3 you have access to the new black and white conversion layer which is the best to use because it has the most control and allows you to apply any color tint you may want all in one layer. Once you open the layer you’ll notice that there are many color sliders to choose from which allows you to adjust many selective areas in the image. You can also move your cursor into any part of the image that you want to adjust and simply by clicking on that spot and by moving your cursor up or down you’ll notice the corresponding color slider changing and the tonal value of that spot lighten or darken. You can also change the tint and saturation of the image with the sliders at the bottom.

With the advent of the black and white layer in CS3 there are many new possibilities open to the black and photographer that did not exist before.