Back in the day when monochrome prints dominated art photography, big names such as Ansel Adams created dramatic effects by using colored filters with black-and-white film. A red filter, in particular, blocks light from the blue sky while freely transmitting the mellow colors of rocks and dry grass. This combination results in an almost black sky while the bleached foreground seems to leap out at the viewer.
1. Accentuate the colors
Begin with a photograph that has a rich range of colors. From the Menu bar in Photoshop choose Image ⇒ Adjust ⇒ Hue, Saturation and push the Saturation slider to +10 or +15.
2. Create a red layer
From the Menu bar, choose Layer ⇒ New Fill Layer ⇒ Solid Color and in the dialog box that opens, pull down the Mode menu and choose the Multiply option (to make the red filter transparent). Click OK, and then when the color picker window pops up, select maximum red. You can do this by looking for the data entry fields labeled R, G, and B. Enter 255 for R and 0 (zero) for G and B. Photoshop creates a red layer, showing you how Ansel Adams might have seen his subject through the viewfinder of his film camera. Remember, you’re going to make everything monochrome in the next step. Bright red will become white, and mid-red will become gray.
3. Convert to grayscale
From the Menu bar, choose Image ⇒ Mode ⇒ Grayscale, click Flatten in the Layers dialog box that appears, and you’ll see the result: a black-and-white image.
4. Tweak the contrast
The image needs more contrast, so, from the Menu bar, choose Image ⇒ Adjust ⇒ Auto Levels, and you’re done.
5. What if you want a different color filter?
Undo twice to get back to the layer you created during Step 2. If the Layers palette is not visible on your screen, choose Window ⇒ Show Layers from the Menu bar.
In the Layers palette, double-click the red thumbnail in the layer directly above the thumbnail of your photo. The color picker pops up. Now you can enter different values for R, G, and B, or click on a color in the picker window. This will be your new filter color.
Repeat Steps 3 and 4 above.
Photoshop 6 introduced a Channel Mixer option, which makes this whole process easier, although harder to visualize. Start with your color photo as before. Choose Image ⇒ Adjust ⇒ Channel Mixer from the Menu bar. Click the Monochrome checkbox at the bottom corner of the dialog box and move the sliders to and fro for instant black-and-white output, as if you were applying filters of any imaginable color.
Would Ansel Adams have approved? Probably not. If it had been this easy, everyone would have been doing it!