Hi everyone.

New AE user here, in the process of creating a software demo. I've looked through several of the tutorials on Adobe TV, consulted the official Help, and was unable to find an answer to my question so I'd like to post it here.

I used Adobe Story to write the narration for a software tutorial, Snagit to record the screen video, put those two together in Premiere Pro. The timing matches well enough, so now I want to apply some simple special effects using After Effects.

Every so often when I talk about a control in the software, I want the screen to dim and only that particular control to be bright.

Being new to using AE, I'm assuming that I can use a mask to accomplish this, but when I apply the mask, everything outside of the mask blacks-out as illustrated here:

http://buckspub.com/ae-list-questions/mask-question-1.jpg

Ideally, I want what's black to be at 50% or 60% opacity so the remainder of the program can still be seen.

I've been reviewing the Help and Tutorials, but maybe I'm just so overwhelmed with information that I'm overlooking the answer that's right in front of me.

If someone could refer me to a tutorial to answer my question, or provide a good string of keywords to help me find the answer it would be greatly appreciated.

Thank you,
Buck