The Photoshop Channels Book

Step 1.

OPEN A RAW IMAGE THAT HAS A PROPERLY EXPOSED SKY (OR PROCESS IT IN RAW)

This technique works in one of two ways: (1) With your camera, on a tripod, you shoot multiple exposures of the same scene (for example, one photo exposed for the ground, then the same exact photo again exposed for the sky), or (2) You shoot the photo in RAW format, then use Photoshop's Camera Raw plug-in to create two different exposures from the same RAW file. In the example shown here, we're opening a RAW photo in Photoshop's Camera Raw plug-in that is exposed for the sky (the sky looks great, but since I exposed for the sky when I took the shot, our buddy Matt Kloskowski, the road, and the rocks behind him are way too dark). Just click the Open button to open the photo.

©SCOTT KELBY

Step 2.

OPEN THE SAME RAW IMAGE, BUT INCREASE THE EXPOSURE UNTIL THE GROUND IS PROPERLY EXPOSED

Now, go back to the original file on your computer, and open it again. But this time, when it opens in Camera Raw, drag the Exposure slider over to the right until the road, rocks, and well…Matt, are properly exposed. You may need to drag the Shadows slider to the left, as well. This will pretty well trash the sky, making it too light, but don't worry, we're going to blend this image (with the properly exposed foreground) with the first image (with the properly exposed sky) to create a photo that's actually outside the range of what our camera could even capture. So, now you can click Open to open the lighter photo.

Step 3.

YOU SHOULD NOW HAVE TWO IMAGES: ONE EXPOSED FOR THE SKY; ONE FOR THE GROUND

You should now have two images: one with the ideal sky (on the left), and one with the ideal foreground (on the right). Now, there are all kinds of masking tricks that would help you merge these two together (if you have the time and patience), but none that will do the trick faster or better than the channels trick you're about to learn.

Step 4.

HOLD THE SHIFT KEY AND DRAG THE LIGHTER GROUND VERSION ON TOP OF THE GOOD SKY IMAGE

Start by dragging the lighter version of the photo over on top of the darker version (using the Move tool [V], of course). Before you just drag-and-drop that photo, you've got to press-and-hold the Shift key, though. Holding down the Shift key beforeand whileyou're dragging-and-dropping ensures that the two images will be perfectly aligned, pixel for pixel, one exactly on top of the other. This perfect alignment is critical to make this trick work.

Step 5.

LOOK AT THE CHANNELS TO FIND THE ONE WITH THE MOST CONTRAST. FIRST, LOOK AT THE RED CHANNEL

Now, it's time to look at the three channels individually and choose which of the three has the most contrast between the ground and sky. First, press Command-1 (PC: Control-1) to check the Red channel. As you can see here, there's a pretty decent amount of contrast between the sky and rocks, but you have to check the other two channels to see if one of them has more contrast.

Step 6.

NEXT, CHECK THE GREEN CHANNEL

Next, check the Green channel (use the shortcut). To me, this one looks like it has less contrast than the Red channel (the sky looks a little darker than the Red channel, and the rocks look a little lighter, making them closer in contrast, not farther away. But hey, that's just me).

Step 7.

LASTLY, CHECK THE BLUE. IT LOOKS LIKE THE RED CHANNEL IS YOUR BEST BET

Lastly, check the Blue channel. There's really no sky in this image, it's just kind of blown out. So, out of the three, the channel that looks the best to me is the first channelthe Red channel. Make note of that, because you're going to need that info about two steps from now. Use the shortcut to get back to your RGB Composite image.

Step 8.

CHOOSE BLENDING OPTIONS FROM THE LAYER STYLES POP-UP MENU

We're going to use the Layers palette Blending Options (in particular, their Blend If sliders) to merge these two channels together. So, choose Blending Options from the Add a Layer Style pop-up menu at the bottom of the Layers palette (as shown here). By the way, you can also get to these Blending Options by simply double-clicking on the layer in the Layers palette, so use whichever method you like best.

Step 9.

IN THE BLEND IF SECTION, CHANGE THE CHANNEL TO RED

When the Blending Options dialog appears (yes, it looks like the Layer Style dialog, but you're in the Blending Options section of the dialog), go down to the bottom where the Blend If sliders are. This is where you choose your contrast channel. Remember how two steps ago we determined it was the Red channel? So, from the Blend If pop-up menu, choose Red (as shown here).

Step 10.

DRAG THE TOP RIGHT SLIDER TO THE LEFT TO BRING IN THE SKY, FROM THE BACKGROUND LAYER IMAGE

Now to blend the nice sky into this photo, drag the top right slider to the left (as shown here). As you do, the sky from the layer beneath begins to bleed into your photo, seemingly taking over your washed out sky, and replacing it with the good sky from the layer below. As you drag to the left, more and more of that sky will appear in your image.

Step 11.

HOLD THE OPTION (PC: ALT) KEY AND SPLIT THE SLIDER FOR A SMOOTHER TRANSITION

Once the full sky is in place, to make sure your blend is smooth, you'll need to press-and-hold the Option key (PC: Alt key), then continue to drag the slider a little further to the left. By holding this key down as you drag, it splits the slider in two (as shown), and it's this split that makes the blend perfectly smooth. When it looks good to you, click OK, and you've done ityou've used channels and the Blend If sliders to create a perfect blend of the two images, without all the masking and painting usually required to pull off a mini miracle like this.