One of the tools that may be used more in photo retouching is Hue / Saturation. This is due to its great utility in the correction of color in product, its utilities in the portrait and the infinity of applications that can take in the photography to give a harmony of color.
For this reason, here you will see an explanation to this tool, so you know how you can make the most of it.
Hue / Saturation / Luminosity
The color model of HSL (from the English hue, saturation, lightness) is an interpretation very close to the way people see color. This model was created by Alber H. Münsell in 1905; and later improved by Tektronix in 1978.
According to this model the definition of the parts also has relation to our way of seeing:
- Hue (Hue) : It is the same color, physically defined by a wavelength ranging from 380 to 780 nanometers. In the scale represented by Photoshop it goes from -180 to 180, and in coloring mode from 0 to 359.
- Saturation : It is how pure or intense that nuance is. The less intense this tone is, the result would be that the perceived color would tend to gray. Physically it is a percentage that is born between the comparison of total and current intensity on the total intensity. The scale in photoshop is guided from -100 to 100 in order to have better control with the result. However, in coloring mode, it goes from 0 to 100.
- Luminosity (Brightness) : Is the light intensity. A great intensity is very bright and we perceive it as white and, if there is no intensity or light, it turns black. Like the saturation, is an average between the maximum and minimum intensity, so its value ends up being a percentage of 0 to 100. The one in Photoshop is called on a scale of -100 to 100 is to be able to have more control of the tool and works on the same scale in both coloring and normal mode.
The main advantage of this model is that it is not a color space such as ProPhoto, Adobe RGB or SRGB. This tool works as a numerical map in three dimensions that allows us to locate a color in one point and take it to another point according to our needs. Hence, it is such a powerful tool.
Exploring the map
Based on the characteristics of the HSL map, the most important thing is to explore and perceive how each adjustment is modifying the color to reach new results.
As you can see in the following images, the first thing we can notice is that to reach a specific tone we could start by matching luminosity . A target will require that we take off intensity, while a black will require that we give it to them.
To change a color we have to take into account the properties of the base . For example: transforming the white a pure red tone requires that the intensity goes down to have a medium gray and then bring the saturation of the color to the maximum to bring it to the desired shade. In the case of black, what you have to do is raise that intensity of light to a medium gray.
However, another pure color will not require a change in intensity or saturation, but will move its value on the tonal wheel . In the case of blue, taking it where it is theoretically the magenta will transform the color to the pure red we are looking for.
Bearing this in mind, when grabbing any other color it is enough to understand how that color is composed to know where to go on the HSL map. In the case of the coffee I used below, the first thing I did was to move the scale to look for a reddish hue. In doing so, the first thing I noticed is that the light intensity of the color was low, so I raised the luminosity bar. There already the color resembled more, but was still low in saturation, and since we look for purity, I decided to raise that value to the maximum to match the tone.
And this was not just to put the pretty colors?
As I said at the beginning, the most beautiful thing about this tool is its diversity in uses . Here we explained before how to use it to create saturation masks in 16 bits , how to change the color of the eyes and even how to use it to make color correction to create photographic styles. It is, in my opinion, the second most versatile tool in the editing program (the first being the curves tool ).
Personally I like to use it to fix skin tones , especially with those people whose skin sprouts and we came out in the photos with red spots all over our face. I also like to use it to change funds. As an example, my portrait is below.
In the example above we can see another very important part of the tool, the selection of color range . Many times we worry about sharpening masks at the tip of a brush and eraser, but sometimes we select a range and degrade it enough to not see the cut enough to obtain a good result.
As always, the most important thing is to practice and see how the settings change the image . Master the controls and find the color logic to make those changes more quickly and intuitively. There is a world of color to explore.