I spoke with new photographer today about saturation today and she had some questions. I thought I would share with you all what we discussed. In my experience, if one person has a question about a topic at least 10 other people have those same questions! So here goes...
Saturation - Color saturation is used to describe the intensity of color in the image.
De-Saturate: To take out the intensity of color in the image.
Sometimes photographers will intentioally overly saturate to pop the color in an image. Sometimes photographer will intentionally de-saturate an image to create mood. A lot of images taken in the 70's were de-saturated! :)
One thing I would personally stay away from is de-saturting skin tones. It makes people look dull and lifeless. If you want the desaturated look on your image you can use a hue/saturated adjustment layer in photoshop and then mask back in your skin tones to taste.
Below I have shown an image saturated 4 different ways. I did this by adding a hue/saturation adjustment layer to each image and pulling the saturation out with the slider to the left.
As you can see, when you completely de-saturate an image, you end up with no color. These images are referred to as a greyscale or a black & white images. I do not recommend achieving black and white images by pulling out all of the saturation. Remember light has a color. Photography is the art of painting with light so, If you rid an image of all color....you are making the light in your image colorless and flat as well. As you can see a completely de-saturated image results in a flat B&W's because the image has been rid of all color.
I prefer to use the channel mixer or a gradient map for B&W's. They keep the "color" of light in tact and therefore give your black and whites more dimension.
Original image saturated to taste for the baby to look natural.
De-saturated about 50%
Channel mixer b&w