What are the concepts of hue, lightness and saturation in photography?

1 hue refers to "the appearance of color". In the visible spectrum, people's vision can feel different colors such as red, orange, yellow, green, cyan, blue and purple. If we adjust the color of an image to a different hue, the whole image will be redistributed into different colors according to its hue, forming a strange world that can't be seen under normal vision.

Brightness refers to the brightness and depth of a color. Generally speaking, the higher the lightness, the lighter the color and the closer it is to white. The lower the lightness, the closer the color is to black. Of course, when the color is close to white or black, the saturation will also decrease, but this does not mean that the brightness will change when the saturation decreases!

Saturation is also called chromaticity or color purity, which means "brightness of color". When the sun is strong, we can use a polarizer to filter out stray light scattered in the air, which can make the image more saturated. On cloudy days, due to insufficient light intensity, diffuse light and colors look impure and unsaturated.