How do I change the brightness/contrast of a mask?

[Sue_Zan404]

I've masked out a person, who is dressed entirely in black, and need the shadows & highlights of the dress to be emphasized so it doesn't just look like a flat black silhouette.  When I try to adjust it by going to Effect > Color Correction > Brightness & Contrast, the panel comes up and I drag the numbers down/up, but the image stays exactly the same!  Am I doing something wrong?  (Yes, I have the right layer & the mask selected).

Thanks.

~ Sue_Zan404

[Mylenium]

Unless effects have explicit references to masks, they work on the entire layer, not just the isolated parts or the mask. In your case this makes no sense, anyway, and would never work. You simply use duplicate layers and mask them suitably, then tweak their parameters. You need to seriously learn some basics here.

Mylenium

[Sue_Zan404]

Well, that was quite rude.  I am relatively new to After Effects, but have done similar tasks rather often; I know the effect won't apply just to the masked part unless I isolate it into a new layer, which I did.  It's not as though my first step for finding a solution was to ask in a forum; I tried for a very long time to get it to work, followed the most beginner-level of tutorials, and followed the steps. 
I'm not just some idiot randomly clicking around. 

Although, I am apparently the idiot who didn't update the program, because as soon as it updated, everything worked as it should. 
But thanks for the attitude

[Rick Gerard]

Sue...

You have very thin skin. Creative pursuits are very difficult for anyone that is easily offended. No offense was intended. You just ran into a mentor that does not waste any time holding your hand. A lot of times, they can teach you the most.

When you have a problem like this it is nearly impossible to understand exactly what you are doing without a detailed description or a screenshot. As I understand your problem, you have footage of an actor in a black dress and you need to color correct just the black dress to increase the tonal range so you can see highlights and shadows.

Assuming that there is detail in the dress to start with, and assuming that you have applied the mask and animated it as needed to the same layer as the dress, and you have added brightness and contrast to the layer, you should see an overall change to the layer if you adjust the values. The change should affect the entire layer until you specify a mask in the timeline using compositing options. If there is no effect on the layer, and Preview Settings for the comp panel are on Final Quality, and you are looking at the Comp Panel and not the layer panel, then something else is wrong and we need a screenshot.

From your description, I am not sure that brightness and contrast is the right choice anyway. For jobs like this, I usually start with curves but I will start with Brightness and Contrast and show you how the setup should look.

Brightness and contrast adjusted to brighten the entire image, mask set to none:

All I need to do is brighten the area inside the mask a bit before I do the rest of the color correction so the mask is set to add and I add Mask 1 to the compositing options for Brightness and Contrast:

Then I applied Curves to finish the color correction:

I have pressed the U key twice to show you all modified properties on the layer so you can see exactly what I have done.

Please let me know if this helps. If you can't figure it out, select the layer giving you problems, press the U key twice, PrintScreen and Paste to the forum. If you are on a Mac Ctrl/Cmnd + Shift + 3 will take a screenshot that you can save and then drag to the reply field on the forum.

[Retro80sGuy]

Why do you bend over backwards to defend a "mentor" who is curt and rude?   What's the point of having a support community if mentors are going to act annoyed by people asking questions?  If that's not his thing, he should go do something else.