ADOBE AFTER EFFECTS 7.0
User Guide
275
To use the Color Range effect
1 Select the layer you want to make transparent, and then choose Effect > Keying > Color Range.
2 Choose the Lab, YUV, or RGB color space from the Color Space menu. If you’re having trouble isolating the
subject using one color space, try using a different one.
3 Select the Key Color eyedropper, and then click in the matte thumbnail to select the area that corresponds to a
color in the Composition panel you want to make transparent. Typically, this first color is the one that covers the
largest area of the image.
Note: To use the eyedroppers in the Layer panel, choose Color Range from View menu in the Layer panel.
4 Select the Plus eyedropper, and then click other areas in the matte thumbnail to add other colors or shades to the
range of colors keyed out for transparency.
5 Select the Minus eyedropper, and then click areas in the matte thumbnail to subtract other colors or shades from
the range of colors keyed out.
6 Drag the Fuzziness slider to soften the edges between transparent and opaque regions.
7 Use the slider bars in the Min/Max controls to fine-tune the color range you selected with the Plus and Minus
eyedroppers. The L, Y, R slider bars control the first component of the specified color space; the a, U, G slider bars
control the second component; and the b, V, B slider bars control the third component. Drag Min slider bars to fine-
tune the beginning of the color range. Drag Max slider bars to fine-tune the end of the color range.
See also
“Color Range effect” on page 464
To use the Difference Matte effect
The Difference Matte effect creates transparency by comparing a source layer with a difference layer, and then keying
out pixels in the source layer that match both the position and color in the difference layer. Typically, it is used to key
out a static background behind a moving object, which is then placed on a different background. Often the difference
layer is simply a frame of background footage (before the moving object has entered the scene). For this reason, the
Difference Matte Key is best used for scenes that have been shot with a stationary camera.
1 Select a motion footage layer as the source layer.
2 Inthesourcelayer,findaframethatconsistsonlyofbackground,andsavethebackgroundframeasanimagefile.
3 Import the image file into After Effects, and add it to the composition. (See “To export a single composition
frame” on page 623.)
This is the difference layer. Make sure that its duration is at least as long as that of the source layer.
Note: If there is no full-background frame in the shot, you may be able to assemble the full background by combining
partsofseveralframesinAfterEffectsorPhotoshop.Forexample,youcanusetheCloneStamptooltotakeasampleof
the background in one frame, and then paint the sample over part of the background in another frame.
4 Turn off the display of the difference layer by clicking the Video switch in the Timeline panel.
5 Make sure that the original source layer is still selected, and then choose Effect > Keying > Difference Matte.
6 IntheEffectControlspanel,chooseFinalOutputorMatteOnlyfromtheViewmenu.(UsetheMatteOnlyview
to check for holes in the transparency. To fill undesired holes after you complete the keying process, see “To close a
hole in a matte (Pro only)” on page 282.)
7 Select the background file from the Difference Layer menu.
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