Basic Photoshop Tools Every Photographer Should Know: Curves

It seems as though quite a few new Photoshop users aren't always sure where to start when it comes to learning the basics of the program. While Photoshop is a vast program, it doesn't need to take years to become comfortable with it. So, with that in mind, I wanted to write a series of posts that will help new Photoshop users learn some of the absolute basics of Photoshop editing.

To start off, I want to talk about the Curves panel. In this tutorial, I am using Photoshop CC, but these steps can apply to CS2-CS6, as well.

The Curves panel lets you edit the overall brightness and contrast of your image. To open a new Curves layer, select Layer>New Adjustment Layer>Curves (if you are not familiar with editing with Layers, check out our post on how Layers work):

As you'll see below, the Curves panel shows a histogram and a graph of your White Point, Highlights, Midtones, Shadows, and Black Point. Each section is exactly what it sounds like: White Point is the whitest white, and Black Point is the blackest black. Highlights are the brighter portion of your images, and Shadows represents the darker portions. Midtones represents everything in between.

Always remember that when you adjust one point in the histogram, another point will be affected. For example, if you adjust your highlights, your shadows will also be affected. Editing curves involves a lot of push/pull, and tinkering until you are satisfied with the results.

To keep things simple, let's look at the RGB (Red/Green/Blue) channel. You can edit various color channels individually, but for now, let's just look at editing the overall RGB channel, rather than individual channels:

Adjusting the Curves will increase the overall contrast of your image, as well as the brightness. In order to make a quick increase or decrease, simply click the midpoint of the diagonal line and pull up to the left (brighter) or down to the right (darker):

Two common types of curves adjustments are the S-curve and the inverted S-curve. The standard S-curve will increase the contrast of your image, which means there will be a noticeable difference between your highlights and shadows. The inverted S-curve will decrease the contrast of your image:

Curves adjustments can be layered on top of one another. Below, I have made three curves adjustments in three different layers:

My first two adjustments were S-curves, but in my third adjustment, I moved only one point on the diagonal line instead of two. As you'll see in the third curves adjustment above, I moved my Black Point (bottom left of the histogram) up slightly - this creates a hazy effect on the image. The reverse is also true: if you move the White Point (top right) down, the image will become darker.

Like I said earlier, these are the absolute nuts and bolts basics of the Curves panel, but more than enough to get you started on making some clean and simple edits, so be sure to play around with the Curves panel on your own to experiment!

If you are interested in actions that will help you beautifully edit tonal values, be sure to check out our PURE Color Workflow.

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