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Multiple Masks Using Knockout

Lesson 13 from: Advanced Adjustment Tips & Tricks in Adobe Photoshop

Ben Willmore

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Lesson Info

13. Multiple Masks Using Knockout

Learn to have more control where an adjustment applies by applying multiple masks to an adjustment layer using a feature known as Knockout Shallow.

Lesson Info

Multiple Masks Using Knockout

let's look at one last advanced idea and that is how can I have as many masks as I want applying to one adjustment layer and have a lot of control. Oftentimes if you work on complex images, you might end up with layer mass attached to an adjustment layer that look as complicated as this. And this is a literal mask that I've had in one of my images. The problem is once I get a mask that is this complex, it's really hard to make changes in the future without messing up what's already in here like here. If I wish that this tree was evenly a shade of gray instead of being more modeled in here, how am I going to do it without getting over spray on the building or without filling in the gaps that are in between this. If these were separate mask where this pump was one mask, the roof was another, the tree was another and then I could control it completely separately. It would be much more versatile. Well, let me show you an example of that here is an image where I have a black and white adjus...

tment layer here and above it are multiple masks. If an option click on the mask, you can see its contents. There's one mask that includes trees. If I go to the mask above it, there's one that contains the sign and a bus go to the one above that. We have little lights and some stars and then finally another that is for the station itself and notice how there are no shades of gray for the most part in any of those mass. Usually a shade of gray would indicate where something is applied partially. Not at full strength. Well these are applied partially. Not at full strength but done in a different way. If I switch between each one of these layers, noticed there's an opacity setting at the top. This one is only hiding the adjustment layer that's below it. 37% of the way the one above it is preventing it 100% of the way the one above that is at 77 1 above that is at 53. It would be as if you had shades of gray of that brightness in each one of these masks and now I can really work on these separately. So how does that work? How do you set this up? So it works this way. Well let's do it. I'm gonna throw away this folder full of adjustments and create one from scratch. I'm gonna do a black and white adjustment. I'm not going to use any of the settings that are in there. Just keep it simple and I'll throw away it's layer mask. Now I'm gonna put that adjustment inside of a folder. Here's the folder icon. The only problem is if you have a single layer active at the time, you click the folder, you'll get an empty folder unless you hold down shift which is what I'm holding when I click there. That takes even a single layer and puts it in the folder. And then above this I'm going to end up making selections and making new layers. So let me make a selection quick. Let's say I want this black and white effect to not apply to the star that's over here so I'll come over and select the star. Hopefully the quick selection tool. Be able to handle that. Then I'm going to create what's known as an empty adjustment layer. What's an empty adjustment layer? It's any adjustment layer that would not change the appearance of your picture at all. So I'm gonna come over here and let's use levels and I'm just not going to move any sliders at all. That doesn't change your picture. So as far as Photoshop is concerned, that's an empty adjustment layer. It just happens to have a mask attached to it because I had a selection at the time it was made. Now I want that layer to poke a hole through this adjustment and so it's the effect of having a mask on this to do that. All I need to do is go to the letters FX choose blending options and right here is a choice called knockout. Usually it's set to none but I'm going to set it to knock out shallow, shallow means only knock through layers that are contained in the same group as this and therefore it's gonna ignore anything else that's outside of this little folder icon knock out deep would knock all the way through every single layer that exists until it hill layer called background. There's not even a layer called background here, so that would cause it to knock a hole all the way through and look like a checkerboard. We want this set to knock out, shout, click OK, now you notice the star is back in color. Let's do that for other portions of this image. I'm going to go back to the original layer and I'm just gonna tell it to select the subject. I have no idea what is going to find but let's just say that that area, I'll just remove it off of the sign that's over here. Okay, this area I'd also like to have that not apply to So again I create an empty adjustment layer. Usually just use levels and don't touch anything. Then I go back to letters fX choose blooding options and I just said it to knock out shallow. Now that is knocking a hole through all the layers that are found within this folder and therefore it knocks a hole through my black and white adjustment layer, But I can change the opacity if I bring it all the way down, it doesn't knock out at all. If I bring it up a bit, maybe I want this black and white to only be removed 50% of the way from that particular area and I can create as many of these as I would like to have it knock a hole through that adjustment layer and I do that all the time because I want really complex results. So let me choose undo quite a few times here or at least in my history panel. To go back to what I started with And just look at what I had here is a black and white adjustment layer and there's four layers like that set up and each one of them has a complex mask on it. If I turn off each one you'll see. This one's controlling the green areas are actually it's controlling the whole station, this one's controlling the little stars that are on the side of the wall, this one's controlling the pumps and this one over here is controlling the trees. Each one is independent. Each one is going to further poke a hole through that black and white adjustment layer. Well, there we go. Advanced adjustment tips and tricks in Photoshop. I'm Ben Wilmore and I hope to see you again on Creative Live

Ratings and Reviews

Alicia Orth

I've been using Photoshop for years and still learned lots of great tips from this class. Would love to see more classes like this.

Eric Johnson

Terrific - lots of great information. Way to go Ben!

Marco Basile

Really enjoyed how succinct and sharp the presentation was. Great information I hadn't seen elsewhere. Thank you Ben.

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