Here’s a photo I took one summer evening at the beach:

Before

Before

I like how the sun is getting ready to dip below the horizon as a boat heads out across the lake, but the colors are quitemuted and dull. They could definitely use a little help.

Here’s how the photo will look after a quick and easy adjustment using a Gradient Map:

After

After

Step 1: Add A “Gradient Map” Adjustment Layer

If you’ve been following along with our tutorials for a while, you know that in most cases, the very first thing we do is duplicate the Background layer, which allows us to work on the image without harming the original pixel information. In this case though, we’re going to be using one of Photoshop’s adjustment layers, and one of the great things about adjustment layers is that they allow us to work non-destructively. In other words, we get to work on the image without actually touching it! Photoshop gives us a complete preview of what the image looks like after making our adjustments, whether we’re using a Levels or Curves adjustment layer to improve overall image contrast, a Hue/Saturation adjustment layer to colorize an image, or a Threshold adjustment layer to find the lightest and darkest parts of the image, but all of the work is actually being done inside the adjustment layer itself. None of it is being done directly to the image.

We’ll save a big discussion about adjustment layers for another tutorial, but for now, just know that nothing we do with the Gradient Map adjustment layer we’re about to add will harm the image in any way, which is why there’s no need to first duplicate our Background layer.

Before we can do anything with our adjustment layer though, we first need to add it, so click on the New Adjustment Layer icon at the bottom of the Layers palette:

STEP 1Photoshop Sunset: Clicking on the “New Adjustment Layer” icon.

Then choose Gradient Map from the list of adjustment layers that appears:

step11Photoshop Sunset: Select “Gradient Map” from the list.

Step 2: Click On The Gradient Preview Area To Edit The Gradient

This brings up Photoshop’s Gradient Map dialog box:

step2Photoshop Sunset: The Gradient Map dialog box.

Photoshop’s Gradient Map feature gets its name from what it does. It allows us to “map”, or assign, different colors to
different tonal values in the image. We can use a Gradient Map to make all dark areas in an image one color, all light areasa different color, and all mid-tone areas yet another color.You can choose any colors you like! In fact, you can divide the tonal range of an image into a rainbow of colors if you want, and since we’re working with gradients (hence the name “Gradient Map”), Photoshop will create smooth transitions between the colors
for us.

When the Gradient Map dialog box appears, it will most likely be set to the “Foreground to Background” gradient as we can see
above, going from black on the left to white on the right (assuming that your Foreground and Background colors are currently set to the defaults). If we were to map this gradient to our image, we’d instantly convert our image into black and white. Infact, if you look at your image in the document window, you’ll see that all the color is now gone (as long as the Preview option is selected in the dialog box):

step 21

Photoshop Sunset: The image appears black and white with the default gradient.

Of course, this isn’t what we want. We want to add reds, oranges and yellows to our sunset, not convert it to black and white, so the first thing we need to do is edit the gradient. To do that, click directly on the gradient preview area:

step22

Credit: Tutorial9