DIY Network

Digital Darkroom: Replacing a Background From "The Whole Picture" episode DTWP-105

	Merge your favorite digital pet photo a the new background for a fun and distinctive portrait.

In the previous lessons on pet portraiture, professional photographer Erin Manning gave advice on setting your camera's ISO to get the best exposure and taking test shots before getting started with your live subjects. She also talked about the best way to light pets for portrait shots and how to choose a suitable background to accentuate the lighting and the look of the pet.

Now Erin demonstrates a digital trick that can be used to change the background -- to almost anything you like -- after the picture has been shot. First she describes how to take the right kind of photo so that the background can later be removed, then she describes a "magic wand" that can be used to digitally replace the actual background with one of your own choosing.

Materials:

Digital camera
Camera owner's manual
Tripod
Clamp lights
Roll of seamless paper, sheet or blanket
Image-editing software

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	Take a few shots increasing and decreasing the light on the background to insure you get an image that the computer can work with.
	Shutter speed: 1/45 sec Aperture: f4.9 ISO: 800 No flash
	Shutter speed: 1/70 sec Aperture: f4.9 ISO: 800 No flash

Shooting a "Removable" Background

Using the computer, you can actually remove your background and replace it with just about any scene you want. This technique is similar to the "bluescreen" process that's used for digital special effects in big-budget movies. It's also the basic process used to separate the weatherman from the weather-map on your local news broadcast.

In order to achieve this effect, you'll first have to shoot your subject making sure that there's good separation between the subject and background. To "separate" the background from your subjects, there are two things you'll need to do:

1. Increase the amount of light on the background behind the subject.

2. Make certain that the color of the background is not anywhere on your subject--e.g., on their collar or object the subject is sitting upon.

Once you get the lighting right, take your shots. Take a couple of pictures increasing and decreasing the light on the background to insure you get a shot that the computer can work with.

	Shutter speed: 1/60 sec Aperture: f4.9 ISO: 800 No flash
	Pick your favorite shot.
	Choose a background.
	The end result.

Digitally Replacing the Background

Now for the fun part--changing the background. In order to change the background of your pet portrait, just follow these simple steps and your pet can be in Egypt or Rome in no time.

Note: There are a number of image-editing software packages available on the market. Most have similar functions and features, but there may be minor variations in how they work. These are the basic steps for the photo-editing procedure shown in this episode that were made using Adobe Photoshop®.

1. Load all the photos you took onto your computer.

2. Choose your favorite image and double-click to open the file. Under the menu bar, select and SAVE AS to give the file a new name while simultaneously archiving the original.

3. Most image-editing programs offer you the capability of working with LAYERS. This functionality is what you'll be using for this project. Under the layers menu, click on the BACKGROUND, and rename it as "Layer." You can now edit the photograph.

4. The MAGIC WAND tool is a color selection tool. By using the magic wand to click on the background of the image (in this case, the green background), you can select the entire background. (Since the background was shot as one continuous tone, it will be easy to select only the background as distinct from the subject.) Once you've selected the background, you can DELETE it.

5. Choose a new background. You can use a photo you've taken or download one from the internet. Keep both the background and pet portrait layers open while you are working.

6. Right click on the pet photo and select LAYER VIA COPY.

7. Select the MAGIC WAND tool and change the TOLERANCE (located at the top) from 0 to 255. The higher the tolerance, the more area the magic wand will select. Somewhere in the middle should work. Just play with it until you select one that works.

8. Start selecting the area of your pet portrait you want to appear in front of the new background.

9. Once the entire area is selected, use the drag tool to drag the image to the background layer you have chosen.

10. Clean up the edges with the eraser tool.

11. Save your work

12. Print

RESOURCES :

PC Photo magazine
Website: www.pcphotomag.com
Online version of the magazine devoted to digital photography and related technologies.

The Complete Idiot's Guide to Digital Photography
Model: 002864235X
Author: Steven Greenberg
Order this book from Amazon.com.
Prentice Hall
Paramus, NJ 07652

Digital Photography For Dummies
Model: 0764506463
Author: Julie Adair King
Order this book from Amazon.com.
Hungry Minds, Inc.

Complete Digital Photography
Model: 1584500077
Author: Ben Long
Order this book from Amazon.com.
Charles River Media
Website: www.charlesriver.com/