Video Opacity / Masking

Opacity: allows you to adjusts the overall visibility of your footage.

Select the Effect Controls tab. Then click the Opacity drop down arrow.

Mask: a system allows you to draw shapes that hide or reveal footage relative to that shape. The Circle and Rectangle buttons draw those respective shapes in your footage. The pen tool allows you to draw your own shape. By default, the mask you drew will reveal footage only within that mask. If you would like it to hide footage inside of it, the Inverted checkbox will make that happen.

Mask Path: allows you to drag the mask elsewhere on the footage.

Feather: option softens the edge of your mask.

Opacity: adjusts the visibility of the footage inside of your mask.

Expansion: allows you to detract or add space inside or outside of the shape you drew.

Blend Mode: allows you to change how pixels in the image are affected by other layers below it. (like Photoshop)