Adobe After Effects CS4 - Manual (Page 483)

477 USING AFTER EFFECTS CS4
Effects and animation presets
Last updated 12/21/2009
Mirror effect
The Mirror effect splits the image along a line and reflects one side onto the other.
Reflection Center The position of the line about which the reflection occurs.
Reflection Angle The angle of the line about which the reflection occurs. An angle of 0° reflects the left side onto the
right. An angle of 90° reflects the top onto the bottom.
This effect works with 8-bpc and 16-bpc color.
Offset effect
The Offset effect pans the image within a layer. Visual information pushed off one side of the image appears on the
opposite side. One use of the Offset effect is to create a looping background from a layer. At Best quality, the offset is
performed with subpixel precision.
Lloyd Alvarez provides a simple expression on the AE Enhancers forum that you can apply to the Shift Center To
property to simulate a poorly timed film projector.
Shift Center To The new position of the center point of the original image.
Blend With Original The transparency of the effect. The result of the effect is blended with the original image, with the
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.
This effect works with 8-bpc and 16-bpc color.
Optics Compensation effect
Use the Optics Compensation effect to add or remove camera lens distortion. Elements composited with mismatched
lens distortion cause anomalies in the animation. For example, tracked objects in a distorted scene don’t match the
scene area because linear objects don’t follow the distortion of the scene.
This effect works with 8-bpc, 16-bpc, and 32-bpc color.
Field Of View (FOV) The field of view (FOV) of the distorted footage. The FOV is relative to the size of the source layer
and the selected FOV Orientation. The distortion amount is relative to FOV. No general rule defines what FOV value
applies to different lenses. Zooming in reduces the FOV, and zooming out increases it. Consequently, if footage
includes different zoom values, you’ll need to animate the FOV value.
Reverse Lens Distortion Reverses the lens distortion. For example, to remove wide-angle lens distortion, set Field Of
View to 40.0 and select Reverse Lens Distortion. Selecting Reverse Lens Distortion enables the Resize control.
FOV Orientation The axis on which the Field Of View value is based. This setting is useful when matching computer-
generated elements to the rendered view angle.
View Center Specifies an alternate center point of view. This setting is useful when using custom lenses that aren’t
centered. However, in most cases, this control should be left untouched.
Optimal Pixels Maintains as much pixel information as possible through the distortion. When selected, FOV values
are no longer reversible.
Resize Resizes the layer when the applied distortion stretches the layer beyond its boundaries. To use this control, first
select Reverse Lens Distortion, and then choose an option. Off doesn’t resize the layer. Max 2X resizes the layer to a
maximum of twice the original width and height. Max 4X resizes the layer to a maximum of four times the original