Cross-processing is a popular technique in the film world, where film was deliberatively processed incorrectly. The results were unpredictable, but often included interesting unnatural colors and high contrast. You can simulate this popular technique with Lightroom's Split Toning controls.
Let's start with the photo shown on the left. I'll convert it to grayscale (right) and experiment with the Split Toning pane controls until I get the cross-processing look I'm after. Figure 7-25 The basic theory is this: You can control the tint and the saturation of the tint applied to the highlight areas of an image separately from those applied to the shadow areas. The Balance slider in the middle controls the range of each. You'll understand the Balance slider better after I show you some examples.
Getting It Right
First I'm going to show you how I got the cross-processing look I want, then I'll show you how the Balance slider works by going to the extreme.
To get what you see in Figure 7-26, I did the following:
Adjusted the Highlight Hue slider until I got the aqua tint you see in the horses and clouds (the highlights). You can hold the Option (Alt) key while you adjust the slider ...