Adobe AFTER EFFECTS CS3 PROFESSIONAL User Manual page 388

AFTER EFFECTS CS3 382
User Guide
Note: You can create a crossfade without applying an effect by animating the Opacity property of one layer on top of
another. However, this technique doesn't work if the frontmost layer has any transparent portions (which allow the other
layer to show through, even when at full opacity). The Crossfade mode creates a proper crossfade between two layers,
even if both have transparent regions.
The effect's transparency. The result of the effect is blended with the original image, with the
Blend With Original
effect result composited on top. The higher you set this value, the less the effect affects the layer. For example, if you
set this value to 100%, the effect has no visible result on the layer; if you set this value to 0%, the original image doesn't
show through.
Specifies how to position the control layer. The layer's quality setting affects Blend only if Stretch
If Layer Sizes Differ
To Fit is selected and if the layers are of different sizes. Stretching at Best quality is much smoother.
Calculations effect
The Calculations effect combines channels of one layer with the channels of a second layer.
This effect works with 8-bpc and 16-bpc color.
The channel to extract and use as input to the blending operation. RGBA displays all channels
Input Channel
normally. Gray converts all color channel values for a pixel to the luminance value of the original pixel. Red, Green,
or Blue converts all color channel values for a pixel to the value of the selected color channel for the original pixel.
Alpha converts all channels to the value of the alpha channel for the original pixel.
Inverts the layer (subtracts each channel value from 1.0) before the effect extracts the specified channel
Invert Input
information.
The control layer with which Calculations blends the original layer.
Second Layer
The channel to be blended with the input channels.
Second Layer Channel
The opacity of the second layer. Use a setting of 0% for the second layer to have no influence
Second Layer Opacity
on the output.
Inverts the second layer (subtracts each channel value from 1.0) before the effect extracts the
Invert Second Layer
specified channel information.
Stretches the second layer to the dimensions of the original layer before blending.
Stretch Second Layer To Fit
Deselect to center the second layer on the original layer.
Ensures that the original layer's alpha channel isn't modified.
Preserve Transparency
See also
"Blending modes" on page 166
Channel Combiner effect
The Channel Combiner effect extracts, displays, and adjusts channel values for a layer.
Note: You can use this effect to view any channel as a grayscale image by choosing the channel from the From menu and
choosing Lightness Only from the To menu.
This effect works with 8-bpc color.
Retrieve values from Source Layer, which can be any layer in the composition.
Use 2nd Layer