“Levels”

To restore the light values in a picture, we use the “Levels” feature.
Broadly speaking, a picture consists of three tones namely high, medium and low. Apart from these there are many levels in between.
The high tones are the dark ones (black), the medium tones (gray) and the lower tones (white). Once you’ve plugged in your camera, you’re already halfway through to recovering an overexposed or underexposed images.

Now, to restore an overexposed picture we have to push the slider button, “Dark tones” to the right. Conversely, for an underexposed picture we have to push the button, “Lighter tones” to the left.
For medium tone pictures place the slider in the middle.

 

The same operations can be applied when certain parts of your photo are to be more emphasized.
For example, if the head of zebra is more emphasized in the picture below you will get a 3D effect.

To open the “Levels” option, click the “Adjust” button in the menu bar, select “Brightness and Contrast” in the drop-down menu, and click “Levels”.

Click “Preview” to see and compare the original image with the modified one.

You work with the “Color” option in the same way.
Once again you will have the option to adjust the brightness of the photo.
The only difference is that you have an additional option, “Channel”.
The default value is set to “RGB”, which is an abbreviation for “Red”, “Green and “Blue”. Which also means that you can change the tonal values of all these three colors. Our picture, or rather our monitor recognizes only three colors the others that you see are mixtures of these colors.
We have two other categories, CMYK and LAB color. The first consists of four colors, the second a mix of RGB and CMYK. But what I mentioned now is far too much to explain here.
Remember that a picture made up of RGB colors is composed of three colors, “Red”, “Green” and “Blue”

If you want to work on certain color then click the arrow pointing downwards and select the color you want from the drop-down menu.

 

“Curves”

It is more complicated to operate with “Curves”. This requires more practice, but those of us who love perfection will surely appreciate this option.
Just click the button “Adjust” in the menu bar, select “Brightness and Contrast” in the drop-down menu, and click the option “Curves”.
A dialog box opens where we can see a diagram showing a diagonal line with two points, one at the top right corner and the other at bottom left corner.
The one on the left represents the light tone and the one on the right, the dark tone.
By clicking on the line we can add anchor points which we in turn can move by clicking and dragging.
The movement of this anchor point vertically up and down is same as the movement of the sliders in the “Levels” option.
If you work with multiple points, move from one point to another and observe the difference.

 

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