On this quick video Julieanne Kost from Adobe, takes a look at how to create a cross process effect using Lightroom.
Cross-processing was originally developed in the film area when you developed an image using the “wrong| type of chimicals to create a uniqe color and contrast look. Today we can emulate this type of effect using digital editing (you can see some examples of digital cross processed images on this flickr page).
Kost start by converting the image to black and white by using the V key, and than she adds split tonening (a bit of color in the shadows and a bit of color in the highlights). Playing with the hue and saturation you can get the cross process effect quickly if you follow Kost’s steps. You can of course return to a colored image to do a colored cross process.