Fake Your Depth of Field

Thumb through any magazine and you’ll find that, no matter the style of the photo, all portraits have one thing in common: The background is gently burred, leaving the subject in sharp focus and the center of attention.

The traditional way to get this effect is to set the camera’s aperture to a fairly wide-open position, corresponding to a small f/stop number. Small f/stops tend to deliver a shallow depth of field so that only the subject that you focus the camera on is sharply focused, and everything else in front and behind tends to blur. I’ve written about this effect in the past; check out “Making the Most of Aperture Mode” for more information.

This week, though, let’s look at how to get the same effect using Adobe Photoshop Elements 6. If you want to see this effect done in Corel Paint Shop Pro, then read “Fake a Soft Background.”

Isolate the Subject

Ready to get started? Find a photo with a prominent subject–a portrait like this photo of my daughter should work quite nicely.

Our goal is to selectively blur the background in this photo, while keeping the subject–the girl and the rocks she’s standing on–in sharp focus. To do that, grab a selection tool. I like the Magnetic Lasso, which lives in the sixth cubby from the top of the toolbar on the left side of the screen. The Magnetic Lasso tends to snap onto the edges of an object as you move it around the screen, so click on a part of the subject and then carefully start tracing it with the mouse pointer, letting the lasso lock on as you go. There’s no need to click as you move, unless you find the lasso trying to snap onto the wrong part of the image. Then you can click to set a keypoint, which tells the tool where to go.

If the Magnetic Lasso goes awry and snaps onto a point that’s not an edge of your subject, there’s no need to cancel the selection and start over. Press the Delete key–that will remove the last point the lasso locked onto. Work your way around, and when you’re done, double-click when you get back to where you started.

Fine-Tune the Selection

If you need to make any “holes” in your selection–such as where someone’s arms or legs part and the background is included in the selection–click the “Subtract from selection” button in the toolbar at the top of the screen (it’s the third shape at the left edge of the screen) and then trace around the part of the selection that you want to exclude.

Finally, it’s probably a good idea to “feather” the selection, so the edge between sharp and blur won’t seem as abrupt and artificial. To do that, choose Select, Feather from the menu and set the effect to about 10 pixels. You’ll want to experiment with this value and vary it depending upon the resolution of your photo.

Blur the Scene

Of course, we’ve spent all this time selecting the subject, while what we’re really interested in is the background. Let’s invert the selection: Choose Select, Inverse from the menu. If you look carefully, you’ll see the selection lines change in a subtle way.

Now it’s time to blur the background. Choose Filter, Blur, Gaussian Blur from the menu. As you slide the Radius control, you can see the blur effect change your photo. For this particular image, a blur of about 2.0 looks good to me.

Hot Pic of the Week

Get published, get famous! Each week, we select our favorite reader-submitted photo based on creativity, originality, and technique. Every month, the best of the weekly winners gets a prize valued at between $15 and $50.

Here’s how to enter: Send us your photograph in JPEG format, at a resolution no higher than 640 by 480 pixels. Entries at higher resolutions will be immediately disqualified. If necessary, use an image editing program to reduce the file size of your image before e-mailing it to us. Include the title of your photo along with a short description and how you photographed it. Don’t forget to send your name, e-mail address, and postal address. Before entering, please read the full description of the contest rules and regulations.

This week’s Hot Pic: “Pennsylvania Monument at Gettysburg,” by Mike Lynaugh, Richmond, Virginia

Mike writes: “If you have ever been to Gettysburg, you will notice that they do not light the monuments at night. I used a technique called “Painting with Light” to illuminate the monument with an ordinary $99 flash. In this case, I used a seven-minute exposure with my camera on my tripod, as I walked around the monument firing the flash all over the structure to get the effect I wanted.”

This Week’s Runner-Up: “Bringing Home Dinner,” by Dave Lake, Clinton, Utah

Dave writes: “I took this photo at Farmington Bay, Utah, where every winter the parks services poisons the carp to help the eagles eat as part of Utah’s wildlife preserve program. I used a Canon EOS 20D with a 400mm lens, pushed to 800mm thanks to a 2X extender.”

See all the Hot Pic of the Week photos online.

Hot Pic of the Month: Each month we choose one of our weekly winners to be the Hot Pic of the Month. For April, we chose “Awaiting the Fall,” by Trey Campbell, from Dallas, Texas.

Congratulations to Trey and to everyone else who won a Hot Pic of the Week last month. To see all the Hot Pic winners for April, view the slide show. Keep those entries coming!

Have a digital photo question? Send me your comments, questions, and suggestions about the newsletter itself. And be sure to sign up to have the Digital Focus Newsletter e-mailed to you each week.