quick and easy photoshop “bleach bypass”

Loved this style when I watched the movie Huo Yuan Jia (Fearless) with Jet Li. Typical of this style is strong contrast, desaturated colors in the highlight ranges, saturated colors in the shadow ranges.

Bleach bypass, also known as skip bleach or silver retention, is an optical effect which entails either the partial or complete skipping of the bleaching function during the processing of a film. By doing this, the silver is retained in the image along with the color dyes. The result is a black and white image over a color image. The images usually would have reduced saturation and latitude, along with increased contrast and graininess.
—Wikipedia

1. Start with your original photo
   
2. Do your usual post processing
   
3. Layer > New Adjustment Layer > Hue/Saturation
   Set the Saturation to -100
   
4. Set the blending mode of the layer to Overlay
   
5. And finished!
   
6. Control the intensity of the effect with changes in blending mode
   Pin Light > Soft Light > Overlay > Hard Light > Vivid Light > Linear Light
   Then fine tune using the layer opacity