Changing contrast in premiere

[Delora]

Hello,

I have a video clip and I want to adjust the brightness and contrast of the clip but with the bottom left corner being more adjusted than the top right (which will have no adjustment). This is to compensate for some lighting where it's much darker in one corner than the other. I'm using Adobe Premiere CS5. I don't have After Effects. (I do have photoshop and I tried to create an alpha channel mask (dark in one corner to light in the other) and I brought that image in, but I don't really know what to do with it now - can't see any way to apply that mask to anything or even know if that was a pointless step. What I considered doing was having a copy of the same video clip and adjusting that so it's brighter and more contrasty and then have some kind of mask or way of allowing me to make part of one clip transparent and the rest less so. Am I missing a simple trick here? I feel like there must be some way to fine tune things so that i'm not just changing the whole screen at once.

[poisondeathray]

The search term you want to use is "Track Matte" . There should be dozens of tutorials on google, and instructions in the help pdf. If you're still stuck after watching the tutorials, don't be afraid to ask