Mask help

[wlopatin]

I am new to VSx10 and am trying to learn about how to use the new mask tool. I have a 5 minute clip in which the subject is too dark but because of back lighting the room looks OK. I want to create a mask of the subject and then apply the levels and/or lighting to try to brighten up just the subject. Here is my problem. Using the mask creation tool, I start at the first frame and "paint" a mask on the subject. Then I click to create mask to the end of the clip. After just a couple of minutes, it looks like it is done but the mask is only on a few frames. As I scrub in the mask creation tool, I can see that the mask in the second frame is very much reduced from the first frame, and so on until after about 5 frames the mask just disappears.

Any help would be appreciated. As usual, Thanks...

[asik1]

This tool is very limited, it can't mask just any arbitrary object 100% . All you can do is tweak the sliders or do a frame by frame correction.