Tutorial #5 - Doutzen Kroes
From 
to
using PhotoShop CS2.
1) Image > Mode > Lab Color
2) Click on "Channels" next to the "Layer" palette. Click on Lightness.
3) Press Ctrl + A, then Ctrl + C.
4) Close the window and press Ctrl + N. (You cannot do anything to a Lab Colored picture. It would revert back to its original form.)
5) Layer > New Adjustment Layer > Brightness/Contrast
Brightness: +20
Contrast: +35
And voila! Nothing really major happened but your black and white image looks has more depth to it. You can play with the Brightness/Contrast a bit until you get your desired result.
Other examples:
to
using PhotoShop CS2.
1) Image > Mode > Lab Color
2) Click on "Channels" next to the "Layer" palette. Click on Lightness.
3) Press Ctrl + A, then Ctrl + C.
4) Close the window and press Ctrl + N. (You cannot do anything to a Lab Colored picture. It would revert back to its original form.)
5) Layer > New Adjustment Layer > Brightness/Contrast
Brightness: +20
Contrast: +35
And voila! Nothing really major happened but your black and white image looks has more depth to it. You can play with the Brightness/Contrast a bit until you get your desired result.
Other examples: