Adobe Premiere Elements 8 - Manual (Page 189)

184 USING ADOBE PREMIERE ELEMENTS 8 EDITOR
Applying effects
Last updated 8/12/2010
Cutoff Sets the opacity of nontransparent areas specified by the Threshold slider. Higher values increase transparency.
You can also use the Luma Key effect to key out light areas by setting Threshold to a low value and Cutoff to a high
value.
Non Red Key
The Non Red Key creates transparency from green or blue backgrounds. This key is similar to the Blue Screen and
Green Screen Keys, but it also lets you blend two clips. In addition, the Non Red Key helps reduce fringing around the
edges of nontransparent objects. Use the Non Red Key to key out green screens when you need to control blending, or
when the Blue Screen or Green Screen Keys don’t produce satisfactory results.
The following Non Red Key settings are adjusted in the Tasks panel:
Threshold Sets the levels of blue or green that determine transparent areas in the clip. Dragging the Threshold slider
to the left increases the amount of transparency. Use the Mask Only option to view the black (transparent) areas as you
move the Threshold slider.
Cutoff Sets the opacity of nontransparent areas that the Threshold value specifies. Higher values increase
transparency. Drag to the right until the opaque area reaches a satisfactory level.
Defringing Removes residual green or blue screen color from the edges of the opaque areas of a clip. Choose None to
disable defringing. Choose Green or Blue to remove a residual edge from green-screen or blue-screen footage,
respectively.
Smoothing Specifies the amount of anti-aliasing (softening) that is applied to the boundary between transparent and
opaque regions. Choose None to produce sharp edges, with no anti-aliasing. This option is useful when you want to
preserve sharp lines, such as those in titles. Choose Low or High to produce different amounts of smoothing.
Mask Only Displays only the clip’s alpha channel. Black represents transparent areas, white represents opaque areas,
and gray represents partially transparent areas.
Combine the Non Red Key with the Blue Screen Key, the Green Screen Key, or the Videomerge effect to smooth out
hard to key areas.
More Help topics
“ Superimposing and transparency ” on page 160
Remove Matte effect
The Remove Matte effect removes color fringes from clips that are premultiplied with a color. It is useful when
combining alpha channels with fill textures from separate files. If you import footage with a premultiplied alpha
channel, you may need to remove halos from an image. Halos are caused by a large contrast between the image's color
and the background, or matte, color. Removing or changing the color of the matte can remove the halos.
Choose the color of the matte from the Matte Type menu.
RGB Difference Key effect
The RGB Difference Key effect is a simpler version of the Chroma Key effect. It lets you select a range for the
target
color, but you cannot blend the image or adjust transparency in grays. Use the RGB Difference Key effect for a
scene that is brightly lit and contains no shadows, or for rough cuts that don’t require fine adjustments.
Color Specifies the color in the video that will be made transparent by the mask.
Similarity Broadens or reduces the range of the target color that will be made transparent. Higher values increase the
range.