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Advanced Masks in Adobe Photoshop

Lesson 1 of 4

Class Introduction: Select and Mask

Ben Willmore

Advanced Masks in Adobe Photoshop

Ben Willmore

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Lesson Info

1. Class Introduction: Select and Mask

Lesson Info

Class Introduction: Select and Mask

We're going to talk about advanced masking. Advanced masking just means advanced selections because selections and masking really mean the same thing. If I ever say selection, all I mean is that I've isolated an area and when I did, the result had little dashed lines around it, that's a selection. If I take that same selection and attach it to something or save it somewhere, well, then it no longer looks like little dashed lines. Instead, it looks like a grayscale image the same width and height as your document where an area that is white indicates what used to be selected and an area that is black indicates what was not selected, and that's a mask. But it's just a stored selection or a selection attached to something, like a layer mask, so selections and masking go together. Well, let's jump in and start masking things in Photoshop. Now, this session is called Advanced Masking, and therefore I'm going to attempt to do some images that you might not consider to be easy. For instance, ...

this one is rather complicated and if you look at how many openings there are in all these places, we have to think about how do you select and isolate something like that. Or this one, if you look at the wings that are there, they have some areas that are partially blurry, some areas you can see through. Or here, you see that tree with every single opening in between the branches? Or here, look at this fuzzy, furry arrangement. How do we end up selecting that without shaving too much of this away to make it simpler? Or here, we have smoke, I want to be able to grab that smoke and use it in a different document. So, let's jump in and get started. So first, I'll start with this image and I'm gonna pick a background for it to go onto, I want to move it onto this background. Now, if I already have that background, it's best to put it in the image to begin with so it is a layer sitting underneath your subject. So I'll select these two layers here in Bridge, I'll go to the Tools menu, choose Photoshop, and choose Load Files into Photoshop Layers. If you're starting in Lightroom, you'll find the same choice available, but you go to the Photo menu and choose Edit In to find it. And after doing that, I should end up with a new document in Photoshop that contains a total of two layers, one for each file. Now it just happened to put the image of the sky underneath. If it had put it on top, all I would have done is drag its name down to change the layer order. And the other thing I might need to do with other images is one image might be a lot larger or smaller than the other and so I'd need to click on one of the two, go to Edit, Free Transform to scale them so they both fit the entirety of the document. But these happen to have already been set up, so I only mention that in case you're working with other images. Now, I want to start off by making just a simple selection and so I'm gonna go over here to the Select menu and choose Select Subject. When I do that, it made a selection for me already and so it seems like this is a pretty easy thing to select, but once you have a selection on your screen, there's a way to preview it to get a better idea of how accurate it is. And when you have a selection on your screen, you can type the letter Q, not Command + Q or Control + Q, but Q all by itself. I'm gonna type that right now, and then I'll zoom up and we'll learn how this really isn't a very accurate selection. You see the gaps in between the feathers and the wings, how there's no red in there, and red indicates an area that's not selected. Well, I don't want the sky that's in there selected. And if you look over here in this area, I notice that parts of the feathers are extending into the red, which means that they're not selected, and so that's not a very good selection in that area. On the neck, it's not bad, and up here near the top, it's not bad, but it's where the wings are that it's terrible. Well, there's a feature in Photoshop that's great with working with furry, fuzzy, and hairy objects, and this would be an example of when I would use it. I only typed the letter Q to turn on Quick Mask mode to preview this, I didn't actually need to make a change while I'm in that mode, so I'm gonna type the letter Q again to get out of Quick Mask. The feature that's gonna help us in this case is one I'll find under the Select menu, and it's called Select and Mask. When I choose Select and Mask, it's gonna pretty much take over my screen. And when you first get into it, you might not see a result that looks like this, it's all gonna depend on what setting you used last for the preview that's here. In the upper-left of my screen, you'll see a small thumbnail image of the layer we're working on and right next to it, it's a little down-pointing arrow. If I click on that, you're gonna find options for previews. The default setting, I think might be Onion Skin, but it really depends on what you used last. There's a choice in here called Overlay, which will look just like what Quick Mask mode is, and I'm gonna use that to start with. When you use one of those previews, if it's the one called Overlay or there's another one called Black or White, then there's an Opacity setting here which determines how much you can see through whatever color is being overlaid, and so feel free to adjust that. I mainly mention it because sometimes people end up coming in and just turn really far down, like at 10%, and so when I turn on a red overlay and you do the same, you barely notice it's happened. Well, that would be because your opacity might be lower. Then you can also change the color of the overlay, that is if you're in the choice called Overlay, then you could click here to change the color. If you're working on a red object, then a red overlay is not very effective, and let's see what we can do in here. There's a bunch of settings that are found down near the bottom here. We're not gonna use most of those in this particular case, you can collapse down entire sections of this to simplify, if you'd like. And what we're gonna do is first, I'm gonna zoom up here and we're gonna tell Photoshop where we need some help, and when we do, Photoshop is gonna take over the decision of how the edge should be masked, and the first thing I'm gonna do is come in here to an area called Edge Detection. If I expand that area, there's a setting called Radius, and this means should it look around the entirety of the selection and give it control of a certain amount. If I bring this up, usually I bring it up about two pixels, sometimes three or four, that gives it control over the edge in just a two-pixel width all the way around the edge. And if you want to see what it's doing, just zoom up, maybe up near this head, and I'll bring it back down so it doesn't have any control yet, and just look at how the red comes up here and touches the object. Then I'll bring it up, I'll give it a lot of control, let me bring it to maybe five or six, and do you see the red changing where it appears? That's because I'm giving Photoshop control in larger and larger areas of the image, but usually giving at least two pixels of control will make areas that are near crisp edges refined and will look better. But let me zoom out, and then in the upper left, you have some tools. And you don't have to start with a selection, you could have made the selection right here in this screen by using the top tool, that's your normal Quick Selection tool. You could use it, click and drag on your image to make an initial selection. But then the tool directly below that is the one I want to use, and that's the Refine Edge Tool. That's the tool I use to give Photoshop control over what's happening. So I'm gonna zoom up on the wing that's over here and decide where did it not do a good job, and I'm just gonna take this brush and wherever I can see the background and it doesn't have red on it, I'm gonna paint like this. Now, when I paint it, all I'm doing is I'm giving Photoshop control of that area and it's up to Photoshop to decide if that red paint should appear or not. So just because I'm painting doesn't mean red paint's always gonna show up, it's just that I'm giving Photoshop control over these areas where I'm painting, and therefore it can make the decision. And most of the time, it makes a pretty good decision if it was a furry, fuzzy, or hairy edge, this will usually do a pretty good job. I just need to tell it where does it need help? You don't want to give it too large of an area 'cause then it can start messing up. Almost done with that wing. Now, that might be where I can see through and if so, I should give it some control. That, I'm not sure if it's a highlight or if I'd be able to see through it, but wherever I can see the background and it's not covered with red is where I'm initially painting. And I think I got most of it, maybe right there and there. Then I'll go to the other wing and I'll do the same thing, and this one, I'm just gonna be a little bit more sloppy with just in case we can get a difference in there where you can tell why it would have been better for me to do it more like I did on the previous wing, where I used a smaller brush and I spent a little bit more time to only get it where I really needed it. I will get a smaller brush for some of these little internal areas, I'm not sure if some of those are highlights on the wing or if it's the sky showing through, so it's kind of you have to interpret it as you see it. All right, then I'm gonna go to the main body and in here, I can see little pieces that I think would be hints of the background that are not covered with red, so I want to cover those to give Photoshop control over those areas. A little bit in there. Then I'm gonna go up top of the head, and I'm just looking for areas where the background is not covered with red. Then I'll do a second pass, in this pass I'm looking for parts of my subject that are covered in red. Anything covered in red is gonna be discarded, and so if there's an area that's covered in red blatantly, I want to paint across it to give Photoshop control over those areas because then it might decide to move the red away. So over here, I can see some areas where the bird is covered in red, so I'm gonna click and start painting there, and it's not always gonna perfectly change it, but anywhere where I can see red covering up parts that I might want to keep, I'm going to paint over it. Now, if it's partial red, that just means it's partially selected and that's fine. It's where there's blatant red that I might want to be careful with, like right up there. All right, I think we're doing pretty good. All right, now at this point, there's a way to see exactly where you've given Photoshop control over the image and therefore you can see if you've given it appropriate control. You do that by going to the settings on the left side of your screen, where you're gonna find a checkbox called Show Edge. Edge means where you painted or where you gave it control by moving up this setting called Edge Detection. When I turn on Show Edge, remember I have this set to Overlay where I have a red overlay. If you don't have it set to Overlay, your view will look quite different, but when I choose Show Edge. Now look at the areas that do not have red on top of them. The areas that have no red is where Photoshop has no control, I'm sorry, other way around. (chuckles) The areas where there's no red is where Photoshop has control and the areas where there is red, it does not have control over what's happening. And so I can look in here and say, well, maybe it should have some control in the tip of this, maybe right there, and I can just decide is there any other areas where it might need control. The main thing that I would be looking for here is are there any areas of these feathers that are extending into the outer red where I might want to paint to give it control. I'm just looking around here and it's looking relatively good, but that gives me an idea of where does it have control over what's happening. But if you look like maybe up on the neck, on the neck that's mainly from that slider called Radius, it's set to two pixels, so that's a two-pixel gap right there, but here, do you see how little pieces are sticking out beyond it? Well, that's where it would be useful for me to just come in here and give Photoshop control of those little parts because otherwise what happens is anything that's touching the outer red is gonna get deleted and in the process of deleting it, it just thinks about anything in the inner red, if it looks similar to what's out here where it's gonna be deleted, than you probably want to be deleted. It gets it confused if we have any part of the subject extending into the outer red, so I'm looking around here for the outer red, any parts where furry stuff is heading out there. Now, usually I don't spend anywhere near this much time because I'm not trying to describe things and try to give you a little bit of the logic that's there, and so most of the time, this is a very fast process 'cause I know what to look for. I'm also looking for areas where the background extends into the inner red and doesn't have any of that, 'cause that's where Photoshop would need some control. But anyway, let's just say that that's good enough. I'll turn off the Show Edge checkbox, so now we're seeing just this red overlay indicating the area that will be thrown away. Now, I'm gonna change my preview, so I'm gonna go to where that little thumbnail image is in the upper left, I'm gonna click and I'm gonna choose the choice of On Layers 'cause remember, I created a layer underneath this that contained the sky I want to put it in, and as long as there's a layer underneath, when I choose On Layers, I should get a preview of what it's gonna look like on that new background, and therefore I can start analyzing what the edge looks like and see if there's any areas that have issues. Now, if you look, the areas where you were able to see where there was no red in between the feathers have been cleaned up now and there's just a few areas that don't quite look right. The main thing I'm noticing is down in here, I see kind of a white halo around the edges of things. That usually happens in an area that would end up being partially transparent. Usually, it's an area that was in motion or slightly out of focus or something similar to that, and you're seeing little hints of the old background kind of clinging to your image. Well, you can continue to paint here with that tool, so if you find like this area, you're thinking that could be a part of the background, well, paint over it and give Photoshop control, there's a chance that it is going to make part of it transparent. Or any of these little white halos, feel free to paint over 'em to see if Photoshop changes what it looks like. But if it's mainly an issue of color, like I think it is right now, then you want to head down here to an area called Output Settings. If you expand the area called Output Settings, there's a checkbox, it's called Decontaminate Colors, and if I turn it on, watch what happens to that area where you can see that kinda grayish-white on the edge of the feathers. Do you notice how it just changed? What it did is it went inside the area that's being kept and it took whatever color it is, maybe two or three pixels inside that object and it pushed it out towards the edge. So therefore, any areas on the edge that are partially transparent that might have hints of the old background in it are now getting colors from a little bit further inside jammed into those spots, and therefore we no longer see the color from the old background. Now, there is an amount slider, and I find oftentimes having it turned all the way up, which is the default, doesn't always give you the best-looking results, so I'm gonna turn it all the way down and we'll see the issue again, and then I'll slowly bring it up, each time I bring it up, I let go and I just pause for maybe a quarter of a second to make sure it's updated, and I usually go for the lowest setting that fixes things 'cause it usually looks more natural at lower settings. But on some images, you'll need to have it cranked really high. If you want to see the difference, just turn off the checkbox on Decontaminate Colors, there's without it, and there's with it. So that's gonna fix a lot of your issues. 'cause if you look up near the neck and I turn it off and on, you'll see that it used to have a little white kinda halo around it, and afterwards, it's gone. When you're done, there is a choice down here called Output To, and if you click, you have many choices. As long as you have not used the Decontaminate Colors checkbox, then you'll have the choice of just getting back a Selection or being able to get it as a Layer Mask. But if you have Decontaminate Colors turned on, then you're gonna find that those first two options are not available, and that's because it doesn't want to do anything that would be permanent to your image, and when you turn on Decontaminate Colors, it's shifting the colors of things, and so now it's limiting my choices so that in general, you're gonna want to go with New Layer with Layer Mask. What that's gonna give you is when you click OK, you're gonna end up with a duplicate layer, so the original one is underneath, and the duplicate will have a mask on it that is removing the background. And there's a nice reason why it does that, and that's so if any of the color shifting that happens, you don't like, then you could do something with that original layer that's here to bring back the original colors. I'm not gonna show you that on this particular image, but we'll probably end up using it on other images. So what did I do here? First, I went to the Select menu and I told it to select the subject of the photograph. Then it did a mediocre job of it. Then I went to the Select menu and I chose Select and Mask, which gave me that thing that took over my screen, and in the upper left, I used the second tool from the top to paint and give Photoshop control over various areas. When it does that, it's thinking about the areas that was outside the selection, the non-selected areas, and it's just looking at what color is that stuff and how bright is it, and if it finds things similar to that, it thinks, "Let's get rid of it." Then it looks at what was inside the selection and it says, "What color is this stuff? "What does it look like?" And it says, "Well, in that area "where you give Photoshop control, does it look similar "to what was originally in the selected area?" And if so, it tries to keep it. And so we try to get it so that region where Photoshop has control encompasses all the areas where the background and subject are intermixed, especially if there's an area that's partially transparent. So anyway, here's our end result, and I don't think it looks too bad.

Class Description


  • Isolate furry, fuzzy, and hairy objects (i.e. animals)
  • Remove the background from transparent objects (i.e. glass)
  • Select objects using Color Range
  • Deal with objects that vary in sharpness
  • Use Select & Mask to refine selections


  • Beginner, intermediate, and advanced users of Adobe Photoshop.
  • Those who want to gain confidence in Adobe Photoshop and learn new features to help edit photos.
  • Students who’d like to take ordinary images and make them look extraordinary with some image editing or Photoshop fixes.


Adobe Photoshop 2020 (V21)

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