Re: CS5, How do I create an ellipse-shaped composition, with transparency outside the ellipse?

using a second layer above the radio waves layer as a track matte should do it.

make a new comp-sized solid and then add an oval mask.

place the new solid above the radio waves solid.

in the timeline, from the track matte (TrkMat) dropdown menu for the radio waves layer select 'alpha matte' and it should clip the radio waves to the alpha of the oval layer.

if you don't see the trkmat drop down, right-click near the top of the timeline (where is says 'source name') and choose columns>modes).

Kevin Camp
Senior Designer
KCPQ, KMYQ & KRCW