Photo Color Correction

Adobe Photoshop Tutorial

1. Levels

The first Adjustment Layer in the Photoshop color management control panel is Levels.

Working in RGB mode, Levels has four sections: RGB, Red, Green, and Blue.

The default section of Levels is the general section of all colors together: RGB.

Then there are three more sections to isolate each of the primary colors: Red, Green, and Blue.

For each of the four sections (RGB, Red, Green, Blue), there are three main parts: Shadows, Midtones, and Highlights.

They are not named in the dialog box, but they are graphically represented by a black triangle (Shadows), a shaded triangle (Midtones), and a white triangle (Highlights) underneath the Histogram.

The three triangles correspond with the three Input Levels dialog boxes for Shadows (first box); Midtones (second box); and Highlights (third box).

In the Levels color management control panel alone there are 12 different areas to do photo color correction: four sections (RGB, Red, Green, Blue) times three parts per section (Shadows, Midtones, Highlights):

(Actually, with the two extra dialog boxes (Output Levels) there are more, but I haven't found those to be necessary for web photo color correction.)

For each part of each section where the control panel has sliders and dialog boxes, they offer a range of 255 different color correction levels from a value of 0 to about 255 for Shadows and Highlights, and 0.10 to 9.99 for Midtones; the default settings are 0, 1.00, 255.

There are two ways to adjust the settings: either by moving the sliders (click and/or drag), or by entering a numerical value into the dialog boxes.

Dialog box values can be increased or decreased using the arrow keys. Shadows and Highlights change by a factor of one or 10 (Shift arrow); Midtones change by 0.01 or 0.1 (Shift arrow).

Use either the sliders or the dialog boxes, whichever you prefer. Large changes are made faster with the sliders; fine tuning is easier using the dialog boxes (and arrow keys).