How To: Mastering Photoshop's Curves

Follow these steps to achieve the ideal tone of your photos.

Step-1

Step-1

Curves was once one of Adobe Photoshop’s most complicated tools, but CS4’s version of the dialogue makes it a snap. Now anyone can use this powerful tool to improve a photo. Simply put, Curves graphs the tones in your image. Control the darkest ones by adjusting the left side of the graph, the brightest by adjusting the right: Pull down the curve on the left, and your darker tones will darken. Lift it on the right, and your brighter tones will brighten. Often, when you use Curves for contrast, your curve will be shaped like the letter S. Why use Curves when the less complex Levels tool or Brightness/Contrast slider seems to suffice? Because Curves makes nuanced adjustments to contrast that give you smoother results and more beautifully toned images.*Step 1* Your first step when editing or otherwise retouching a picture in Photoshop is to get the contrast right. With a boost in contrast, this flat image will start to sing. Adjustment Layers in CS4 are easier than in previous versions, so use them. Create a Curves Adjustment Layer by clicking on the Curves button in the Adjustments Panel (circled). When you choose that button, an Adjustment Layer automatically appears in the Layers Panel.
Step-2

Step-2

*Step 2 *As in Levels, it’s easy to add contrast when you use the histogram as a guide. Grab the black arrow (circled), and pull it to the right until it lines up with the beginning of the bumps on the left side of the histogram. This will ensure that the darkest tones in your photo are actually black. Then click on the white arrow, and drag it to the left until it lines up with the beginning of the lumps on the right (not shown), making the lightest tones in your photo close to true white.
Step-3

Step-3

*Step 3* Now we have improved the image, but we can do more. The tacksharp pollen in this flower is the picture’s focal point. To make it really stand out, use it to determine the way you further refine the contrast. Zoom in. Then grab the little pointed finger in the top left corner of the Curves dialogue. Click on a bright point in your picture, and drag up. Watch as the whole image gets brighter, based on the tone you chose. Note, also, that the point on the Curve where your adjusted tone lies is now marked.
Step-4

Step-4

*Step 4* Once you darken the shadows, you’ll really see your photo start to pop. With that little hand still selected, now click and drag down on a shadowy area of the pollen. Keep going until those tones are as dark as you like them.
Step-5

Step-5

*Step 5* Finally, zoom out. Do you need further adjustments? Now that you added points to your curve, you can click on them directly and pull them up or down to refine your image. You can also adjust tones in your image, even if you don’t know where in the image they lie. In this case, the highlights and shadows are looking satisfactory, but it's clear the midtones could be a little brighter. These can be adjusted by working with the center of the curve. To make them brighter, click directly on the curve to add a point, and drag it upward until your photo is just the way you like it.*Quick Tip* Still confused by Curves? The best thing to do is experiment—pull up or down on different areas of the curve and watch what happens. If you’re not sure where to begin, try some presets, included for the first time in Photoshop CS4: Once in Curves, grab the Curves pulldown menu (initially set at Default). You’ll see a few options, some more aesthetically helpful than others. Choose Negative, and the curve line flips—now it goes from top left to bottom right, and all your picture’s tones are reversed. You probably won’t ever want that look, but watching it happen will help you understand how this tool really works.