Magic of Luminosity Blending Mode

Recently I´ve read some tutorial and find out really interesting use of Luminosity Blending Mode.

"The Luminosity blending mode applies the luminosity (brightness) of the blend colors to the base image while retaining the hue and saturation of the base image. Luminosity is the opposite of the Color blending mode."
From: About.com

Increasing the Contrast

You can increase the contrast with this Blending Mode very easily and in a really natural way. How to do it?
Add new Black/White Gradient Map on the top of your layers and change the Blending Mode on Luminosity.

Bellow you can see example photo to see how the whole effect looks.

You can move with the Colors Stops to increase or decrease the contrast. You can also use dark grey instead of black and light grey instead of white to get lower contrast.

Adding Lights and Shadows

The next thing how I start to use Luminosity Blending Mode is to create lights and shadows in my manip. According to me it makes more beautiful colors then using grey layer with Overlay Blending Mode. Grey layer sets to Overlay tends to oversaturated the colors.

When you´re adding lights and shadows throught Luminosity Blending Mode you have to paint with black and white and really low opacity (arround 3%) or with different shades of grey.

Other Tips From The Internet

Method used to improve tone: A simple way of doing this with skin is to use a channel mixing layer set to mono the green channel +100 (as attached). Then set this to Luminosity blending mode. This often improves the skin tones.
Resource: RetouchPro.com

One of the biggest uses for the Luminosity Blend mode is during sharpening. Sharpening can produce color halos. By sharpening on a separate layer and setting the blend mode of the sharpening layer to Luminosity, only the luminosity of the image will be sharpened. This will eliminate any color halos.
Resource: Ronbiglow.com