How Does Curves Work ?

ok so i see all these tuts with a curves adjustment layer step and i am like wtf....

what am i supposed to do here ? there is like a grpahy diagonal line and some dots with some random shading in the bottom ....
what exactly does it do and how do you know what you are doing

 

Well usually the curves layer is used to give a piece more contrast and depth. It's like playing with brightness/contrast adjustment layer but it gives way more control. It's really hard to explain but I can tell you that by moving the line towards the bottom-right will make it darker and moving top-left will make it lighter. Try not too move it too far from where it starts or it'll make a big change on your piece, unless you want a specific effect.

 

Curves adjustment is like a levels adjustment but only better. It has a few menus from the drop down. The normal one which is the black line, then an Red, Green, and Blue for RGB.

These let you control the amount of color and contrast in the particular photo or picture. In the default menu it opens, putting the line up will increase it in brightness, down will darken it.

You have to be careful with how much strength you actually put into it.

Usually, this is enough to give it that extra edge.



The color sliders work easy, you can either add more red, or take away red, add green, or take away green and add blue or take away blue.

Experimenting is the best way to see how the thing actually works.

 

thx for explaining nauron. yeh i will try experimenting... its just that when i use it it just looks like i used a brightness contrast layer except it is more uncontrollable.... i will try this out soon !

 

try to chance the channel to get über cool and controllable color changes
edit: Ah darn Neuron covered that too was not fully reading his post.

 

I just use curves to edit photo coloring,

before:
http://i27.tinypic.com/jjkwvq.jpg

after:
http://i32.tinypic.com/2d6rs4w.jpg

 

The Curve is basically a graph translating one color value to another. The default diagonal line (a straight curve) means that each pixel is translated 1:1—a dark pixel is still dark; light is still light.

As you add and move points on the curve, you change how each value is mapped. Shifting the curve towards the bottom right makes things darker; shifting to the upper left makes things lighter. If you were to turn the default curve upside-down (going from upper left to bottom right), you would invert the photo. A U-shaped curve would make the darkest and lightest regions bright, and the midtones dark, an unusual result.

The histogram (in the background of the curve) shows you where your highest and lowest concentrations of brightness are located. Placing a point on the curve corresponding to a peak or valley in the histogram allows you to squeeze or expand the color range at that region (for instance, to reveal more detail in shadows, or to crush all highlights to white).