In the days of the darkroom, smart photographers didn't settle for simply making a pleasing black and white print. They took their silver-halide process one step further and toned prints to make them last longer. This archival processing had an added benefit: the resulting tones—blues from one element, pinks, browns and golds from others—added to the images' beauty. Some toners impacted highlights predominantly, while others affected the darkest tones. Used together, a black-and-white image could be split toned—one color in the highlights, another in the shadows—and a beautifully rich and vibrant print was the result. The most common techniques involved using a warm tone contrasted with a cool one—say gold tones in the highlights and blues in the shadows. We digital photographers are lucky: not only can we keep our hands dry while we split tone our images, but we have several different ways to make beautifully split-toned black-and-white photographs using almost any colors we'd like. Here are three of my favorite digital split-toning approaches.
These manual edits are generally no problem for me, as I've incorporated them fairly seamlessly into my workflow—just as countless other RAW shooters have. But the other day when I accidentally shot a whole assignment with my camera set to capture JPEGs, I learned something in the processing of those images about what I'm doing—or more specifically, not doing—when it comes to processing my RAW image files.
1. Lightroom. It wasn't until I began using Lightroom that I regularly began split toning my black-and-white images. Why? Because Lightroom makes split toning incredibly easy. In the Develop module, there's even a whole section dedicated to split toning, and it couldn't be simpler. There are two main subheads—Highlights and Shadows—along with hue and saturation sliders for each. There's also a tiny color swatch that, when clicked, allows you to visually choose a color to use for the toning. This is the easiest approach with the hue and saturation sliders used for fine-tuning the color once selected. (It's almost always preferable to lower the saturation if you want to keep the effect on the subtle side.) The Balance slider in between adjusts the overall balance of the split—on the one end emphasizing the tone in the shadows, on the other the tone of the highlights. With these simple tools, it's possible to make split-toned images from imperceptibly subtle to over-the-top outrageous.
2. Photoshop Duotone Mode. To access Photoshop's Duotone mode, you need to start with an image that's been converted to grayscale. It's not enough to desaturate an RGB image; it must first be converted into grayscale mode. Then, found just above Grayscale in the Image>Mode menu, click Duotone to bring up a dialogue box that allows you to select ink colors. While you can use a color picker to select these tones, I prefer some of the presets accessible via the drop-down menu at the top of the box. You can even start with a preset and then modify it by adjusting the overprinting, the curves of a particular color or even by adding a third or fourth tone. These tritones and quadtones, in fact, are a great way to emulate Lightroom-style split toning, as they maintain a solid foundation of pure black and pure white. Without them, the images can take on more of a funky special effect appearance—which might be just the look you're going for. Once you've achieved the look you like, convert the image back to an RGB file (again in the Image>Mode menu) so it can be saved as a JPEG or TIFF.
3. Photoshop Adjustment Layers. With the Adjustments palette open, clicking on the Color Lookup Table icon will create a new adjustment layer and open the color lookup table (CLUT) properties window. There are many CLUT options that convert black-and-white photos into toned images, but only a few that truly split tone them. Click the second or third radio button, the Abstract and Device Link options, and then close the pop-up window to choose from one of the preset options like Sienna-Blue, Gold-Crimson or Turquoise-Sepia. The resulting image tends to be fairly subtly split toned, and to increase or decrease the intensity you can use another adjustment layer—Hue-Saturation. To have even more split-toning options via color lookup tables, Adobe Creative Cloud subscribers can create their own CLUTs via SpeedGrade color correction software. It may have been built for video, just like color lookup tables themselves, but the results sure do work well in photographs—especially for mimicking this old-school darkroom device.