By Dave Johnson
April 14, 2010

SAN FRANCISCO – Here in the Pacific Northwest, the sky rarely cooperates when I try taking outdoor photos. When it isn’t raining, it’s usually overcast. I can choose to live with a gray ceiling in my photos, or I can get creative. If you’re in a similar situation, you’ll be happy to know that it isn’t too difficult to transform even the most boring sky into a blue canopy speckled with clouds. Since I’ve already described how to replace the sky with a real photo, you’ve probably stockpiled blue skies for (pardon the expression) a rainy day. This week I’ll show you a little-known tool in Adobe Photoshop Elements that can generate a fake sky on command.

Isolate the Sky

To get started, you’ll need a photo with an underwhelming sky. Ideally, choose a photo in which the sky is distinct and easy to separate from the foreground. I’ll use this photo, since the uniform gray sky will be easy to isolate from the buildings and waterline.

We need to select the entire sky, but exclude any foreground objects that we don’t want to “lose” in the final photo. There are a lot of ways to select a region of a photo, but I’ll use the Magic Wand Tool here, since the sky is so uniform in color. When you click in your photo with the Magic Wand, it selects all the nearby pixels that share a similar color–and you can control how similar those colors are using the Tolerance setting.

Here’s what to do: Click the Magic Wand Tool, which is the seventh from the top of the Tools toolbar on the left side of the screen. In the Options palette at the top of the screen, set the Tolerance to about 15. Depending upon your photos, you might need to raise or lower the setting to get good results.

So far, so good. Inspect the sky. Did you get it all? Did you get too much? If you need to add more bits of the sky to your selection, click Add to Selection at the very left of the Options palette and click on the part of the sky you want to include. (You might need to lower the Tolerance at this point to prevent accidentally grabbing too much of the photo.) If you need to remove a bit of the photo from your selection, click Subtract from Selection, lower the Tolerance, and click on the part you need to remove.

Fiddle with the Add and Subtract controls until you are satisfied that you have the whole sky (and nothing but the sky) selected.

Set the Sky and Cloud Colors

Now it’s time to set the color of the fake sky and clouds. Double-click the Set Foreground Color square in the color palette at the very bottom of the Tools toolbar.

This will be the cloud color. You can make your clouds any color you like from pure white to dark gray, or anywhere in between. For this particular photo, I think a bright gray will look best–it will make the clouds look a bit “dirty” and more realistic. Enter 240 in each of the R, G, and B fields to generate an off-white tone, and click OK.

Now for the sky color. Double-click the Set Background Color square and enter R, G, and B values that add up to the particular shade of blue you’re looking for. Start with 110, 186, and 225, for example. These are values that I’ve found work through trial and error. Feel free to experiment on your own-you might find levels you like better.

Some photos might work better with a different shade of blue for the sky. If you’re taking a picture of the ocean, for example, try sampling the water color and using it as the basis of the sky. To do that, click the Eyedropper Tool (fourth from the top of the Tools toolbar) and click in the water. That sets the foreground color. Next, click the Switch Foreground and Background Colors arrow (which is right next to the foreground and background squares), and set the foreground color to a cloud color.

Add the Sky

Now we’re ready to color the sky, which should still be selected. Choose Filter, Render, Clouds from the menu. Immediately, you should see a random sky-and-cloud pattern appear in your selected region.

To fine-tune the sky, choose Enhance, Adjust Lighting, Levels, and use the Levels tool to correct your fake sky. You might want to move the slider on the right a bit to the left to brighten the sky, for example, and then fiddle the middle slider until everything looks realistic. Here is how my photo turned out.

As you can see, these clouds in this case are not random enough to look convincing when used across a large stretch of sky, but try to apply this in photos in which the sky is a smaller part of the image–as always, experiment on your own.