Brush the selection into a mask

[Marco1990]

Hello all together, 

I want to work with luminosity masks. I already created them, but now I want to brush into my mask only the selected area. But my problem is, that the brush tool doesn't stop at the borders of my selected area, it always fills the whole mask (not only the selection). I hope you can understand my problem and maybe help me by solving this. In the attachement is an example. I only want to brush the selection.

Thanks a lot! 

Edited June 22, 2019 by Marco1990

[smadell]

In most cases, luminosity selections don't limit the pixels that are selected. All of the pixels in a layer are selected. However, pixels vary in the amount they are selected. So, in a "Lights 1" luminosity selection, the very white pixels are fully selected (100% or thereabouts) while the very dark pixels are selected only minimally. The "marching ants" you are seeing in your luminosity selection is really only the margin of where pixels are 50% selected or more. And, since all of the pixels are selected to one degree or another, you can paint on all of them.

However, the answer to your problem is really much simpler than that. Once your luminosity selection is made, open the "Layers" panel and click the " + " sign at the top. From the drop-down menu, indicate that you want to add a Mask layer. The mask you add will inherit the luminosity selection perfectly. No painting needed.

[Marco1990]

12 hours ago, Marco1990 said:

 

Thank you for you're reply. I've already tried this and this works fine. But I worked with photoshop before and my work flow was to brush it with the brush tool so I was a little confused and didn't know that the selection works like this.

Edited June 23, 2019 by Marco1990

[smadell]

 

 

Marco...

You CAN paint in your mask, exactly as you'd seem to like. There are a couple of caveats, though (and I assume this is the case on the desktop version as well, and may also be the case within Photoshop (but I don't really know much about PS)).

When you have a luminosity selection active, the pixels are selected in varying degrees. Therefore, the paint brush will act as if it's got varying degrees of opacity attached. When you paint on your mask with the luminosity selection active:

1) You should set the Opacity of the Brush to 100%. Choosing anything less will diminish the intensity of your mask, and will give you the wrong result.

2) You should set the Flow of the Brush to 100%. This is mega-important. Anything less than 100% will cause the overlapping parts of your brush strokes to "build up" and give you bad results.

3) Increase the size of your brush - this is for convenience's sake. Also, I would use a hardness of 100%, but this too is for convenience.

4) Paint your mask in ONE PASS. If you make a brush stroke, lift, and make another, you will create a built-up effect where the mask is "magnified." Again, not what you want.

Here's a video of the process. (When I created the luminosity mask, I used a "Darks 1" luminosity selection with a macro.)

EDIT:

I realized after posting that I screwed this up a little bit. It's all correct, with one major flaw. When you do this, create an "empty mask layer" (i.e., one that is filled with black) and when you paint your brush should paint with white. Oops...

[DM1]

6 hours ago, smadell said:

realized after posting that I screwed this up a little bit. It's all correct, with one major flaw. When you do this, create an "empty mask layer" (i.e., one that is filled with black) and when you paint your brush should paint with white. Oops...

Or possibly invert the mask in Channels studio?

[smadell]

or that...