Bair Art Edition's Tutorial on:
Adjusting Color & Exposure
In Adobe Photoshop
Color Adjustment: Hue/Saturation
So far I hope I've berated the point that Color Balance is just what name implies, a fine balance. It should be apparent by now that most color adjustments made to the image will directly affect the rest of the color in the image. For example, you can't seem to increase the amount of Green without decreasing the Magenta in an image.
This problem is called "crossover," and can be very frustrating if, for instance, you like the amount of Magenta in an image, but want to increase the Green.
Photoshop has two powerful tools that will aid you in this battle, and will decrease the amount of crossover. They are the Hue/Saturation tool (discussed in this section), and the Replace Color tool.
Your first choice will predominantly be the Hue/Saturation tool, with your second line of attack being the Replace Color. This is because the Hue/Saturation tool is available as an adjustment layer (follow that link if you don't know what that is!). That means your adjustments can be reviewed, toggled on and off, toned down in opacity, and "erased" where needed; all without changing the background file's information.
Replace Color on the other hand, will change the document's information, and is permanent.
How to Access Hue/Saturation
The Hue/Saturation tool can be found under the menu Image/ Adjustments/ Hue/Saturation.
We will be using this same tool, but, of course, applying it as an adjustment layer.
Either go under Layer/ New Adjustment Layer/ Hue/Saturation
Or on the layers palette (accessable in Window/ Layers) click on the half white & Black circle and choose "Hue/Saturation." (The two layers in the image are adjustment layers).
This tool has three powerful controls: Hue, Saturation, and Lightness.
It also has a pop-down menu that is the key to it's usefulness. This pop-down menu allows you to adjust all the colors, or one of the six we keep running into: Red, Green, Blue, Cyan, Magenta, and Yellow.
Unless you are trying out some strange effects, I would suggest that you never use Hue or Lightness when you are in the "Master" channel. Hue does weird things when all of the colors are involved, and lightness may look like it does a nice job at changing the exposure, but it doesn't. If you, for example, darken the image using Lightness in the "master" channel, the white point disappears, and begin to loose any area's defined as white. It is better to "compress", also called "pinch" the values using Levels, or Curves
Those two controls are, however, very effective when dealing with individual colors.
As far as the Saturation control goes, the application is very simple: the control either increases or decreases the saturation of the image as a whole.
Saturating, or Desaturating are simple concepts. When you are desaturating the image, you are maintaining the tonal value of the pixels (where they stand in a gray-scale), and at the same time you are steadily decreasing the contribution that color is making to the pixel.
This effect can be seen in full Desaturation, partial Desaturation, and selective Desaturation as demonstrated in the following pictures (all of them received a boost in exposure using the Curves technique, as desaturation results in a darker image):
Complete Desaturation is just that, I was in the "master" channel, and took the Saturation down to "-100". The other techniques, including Selective and Partial Desaturation will be covered more fully in a black and white/handcoloring effect tutorial that will soon be posted.
As far as Saturation goes, you are doing the exact opposite of what Desaturation did. Whereas in Desaturation, the tonal (gray-scale values) remained constant, while the color contribution was decreased; now the color values are instensified by the gradual removal of the contribution of black:
These are the other sections of this module:
, Bountiful Utah Weddings
Color Balance and White Balance - An introduction to this module. Covering the basics of these two concepts, including a basic explanation of color and light.
- Using the Color Balance Tool - A nice tool for correcting global color casts. This is not as powerful as using levels when it comes to White Balance, but is better for color adjusting specific tonal ranges (shadows, midtones, highlights).
- Using Levels to Correct White Balance - how to powerfully correct for white balance as well as fine-tuned color balance.
- Using Curves for Color Adjustment - Here we go with curves again! The extremely versatile, yet hard to become accustomed to, tool.
- Using Hue/Saturation for Color Control - Advanced - A highly under-used tool for how powerful it can be in doing selective color adjustment that by-passes the crossover problem!
- Replacing Color - The final word in color adjustment! When all else fails to work, and crossover seems unbeatable, this tool takes the cake. The only drawback is that it isn't available as a layer.
- Painting Color Casts The ultimate way to change a color! This technique will become your best friend. It allows tou to change color casts in specific locations and to precise degrees.