Higher saturation relates to the intensity of colors, a saturated color is vivid, while lower saturation level gives images a washed out look, more pale. While subjective, the value of saturation can be associated with different emotions: highly saturated colors seem more intense, bold, or brave. Low saturation seems more delicate, gentle or even set aside.
Saturation is often paired with brightness and contrast in the user interface.
You can see it as the most basic tool affecting the core element of post-processing color. A saturation tool works as a single slider and I advise not to increase its value too much because it is affecting the whole picture uniformly.
However, when you are about to transform a photo into a black and white picture, it’s a different story: this tool becomes very relevant ! Indeed, when you slide down saturation to zero, you will in fact remove all colors.
Be careful though that if you increase saturation too much, some artifacts may appear depending on the underlying quality of the photo you are working with.
When to use: typically, pop art makes use of very saturated / vivid colors, especially red. Black and white needs it to reduce saturation. Otherwise, use it when you feel the picture would benefit a more colorful rendering. Saturation is somehow tightly related to feelings and emotions. Below we will see how to selectively modify color saturation.