Using Photoshop to convert color images to black & white is a very simple process. Some would say to just open a color image and then convert it to grayscale. It works, but not very well and leaves no room for adjustment and also will render the original color image useless. One of the best ways I know of is to use Adjustment Layers in Photoshop. This way the original Image retains all its color information and the final result can be manipulated.
Follow these easy steps.
Open a color Image in a new Photoshop document. It will now be the Background Image in the Layer Palette.
Create a Hue/Saturation Adjustment Layer. Do this by clicking in the Layers Palette. You will see the half black circle at the bottom. Click and then choose Hue/Saturation.
A dialogue box for Hue/Adjustment will appear. Leave settings as they are this time. We will make adjustments later. You will notice the new layer created above the background layer after you “OK” the Hues/Saturation dialogue box.
Now, create one more Hue/Saturation Adjustment layer the same way as the first. This time though slide the Saturation slider all the way to the left. This will make that layer look black & white. Then click “OK”. You know have two adjustment layers above the original color image background layer.
Now change the middle Adjustment Layer to Color. Where the mouse is pointing in the image below, you need to change that from “Normal” to “Color”.
Now double click the left box visible in the middle layer (looks like vertical black and white smears next to the eye) to bring up the Hue/Saturation Dialogue Box Again. Here we will adjust this time. Try sliding the “Hue” slider around until you are happy with the results. You can of course adjust the Saturation slider and also the Lightness slider to get the results that look best to you. By adjusting the Hue slider, you are changing what colors Photoshop “sees” as black & white.
That’s it! Your original color layer is intact and can be adjusted anytime if you save the .psd document for future editing.