Join Seán Duggan for an in-depth discussion in this video Using a gradient mask, part of Replacing a Sky in Photoshop.
- Once you've identified a new sky image that you feel will work well in your main photograph, the next step is to blend the two together, so that the new sky replacement is convincing. The primary way to achieve this using non-destructive editing techniques, is to use a Layer Mask. In many cases, a Layer Mask will begin with a selection of an area in the image. But for some sky replacements, you can skip that part, and use the Gradient tool directly on an empty Layer Mask. So an area you need to think about blending in a new sky into a photograph, the horizon edge and the simplicity or complexity of that horizon edge, will determine how simple or complex the masking job will be.
A Gradient Mask will work well when there is a pretty simple and straightforward horizon line to deal with. So, something like this image here, or, if I turn that Layer off, we can see this other Layer below, that also has a relatively simple horizon edge. Images where there are a lot of objects that extend up into the sky, and appear in front of the sky, so trees, or buildings, cities, things like that, that presents a much more complex edge where a simple Gradient Mask wouldn't really work that well.
Now, both of these photographs were taken on the coast of Maine, and interestingly enough, they show the exact same boat. And, the story here, is that I was going to take a ferry out to one of the outer islands, and the weather forecast called for some rain to be coming pretty soon. And sure enough, about 25 minutes after I took this photo, the clouds showed up and it started raining. So, I really like the clouds in this picture, but I kind of like the arrangement of the boat, and that other part of the island in this picture here.
Fortunately, it's a fairly simple job to blend those two together. But I just really like the irony that this is the same boat in the same location, just about 25 minutes apart. And the fact that these pictures were taken so close together, and that it is the same lighting, the scale, and the perspective works very well, means that this will all yield a very successful sky replacement. So, the first thing I'm going to do with this top layer turned off, as it is now, is I'm going to show my rulers, by choosing Command-R on a Mac, or Control-R on Windows.
And I'm going to click in that ruler at the top, and drag down a guide to roughly about the horizon line, here. Next, I'm going to click in the ruler and drag down another guide, and position it just about the top of the trees. So, this lets me know the area where my blend has to be, because once I turn the top Layer on, as I'll do so now, I'm not going to be able to see that. Now, I'll want to position this Layer a bit differently, so I'm going to get the Move tool, and I'm going to lower the Opacity of this Layer to roughly about 50, 60%.
And that just allows me to see through, and I can see how I want to position this. So basically, I do want to have those clouds coming down, something like that looks pretty good. Alright, I'm just going to tap 0 on the keyboard to return my Opacity back to 100%. Next, I'm going to add a Layer Mask to this top Layer, by clicking on the Add Layer Mask button at the bottom of the tool panel. It comes in as a white Layer Mask, which just means it is showing the entire Layer right now.
I'm going to tap G on the keyboard to get to my Gradient Tool. And then, up in the Gradient Options bar, I'm going to click on the third icon in from the left, here, in the top row. That's the black to white Gradient. The first two Gradient swatches are always based on whatever your foreground and background color happen to be, so they may not always show up as these colors. Next, I'm going to make sure I have the Linear Gradient Style selected, that's this first little icon here.
I'm going to make sure the Mode is set to Normal, the Opacity is 100%, and I want to make sure that Reverse is not checked. So, in a Layer Mask, black will hide the Layer, and white will show the Layer. So, if I'm starting out with a Gradient that goes from black to white, I want to start my drag right about here at the lower guide line. I'll just click and drag upwards. So, where I first clicked is going to be my starting color, black, and where I end, which is going to be on the second guideline here, that's going to be the ending color of white, in the Gradient.
Everything in between those two points will be the actual Gradient, or that gradual transition. And we're nearly done. Let me hide the guides by using the shortcut of Command-;, or Control-; on Windows. That looks pretty good, the one problem we have is there's a little bit of the clouds that are showing up on top of those trees, and it's just looking kind of foggier, or smoky there. That might look good in some cases, but I'm not too pleased with it. Fortunately, there's a really easy fix. And that fix works because these trees are much darker than the cloud Layer on top of them.
So, what we can do is, we can use a nice Blend Mode trick. With this top later active, the cool clouds Layer, active, I'm going to come up to Blending Mode menu, and I'm going to choose Darken. And there we go, it's fixed. So the Darken Blend Mode is comparing the pixels on one Layer with whatever is underneath it, and only showing the pixels that are darker. And in this case, that lets those trees show through, and we have a really beautiful blend. In the case of these two images, the simplicity of the horizon, combined with the visual appearance of both the original sky, and the replacement sky, which was taken only about 25 minutes later, meant that I could use a very simple Gradient in a Layer Mask to create the blending effect.
Not to worry. With Photoshop you can replace a sky that doesn't work with one that does. In this course, photographer, author, and educator Seán Duggan shows you how to perform this common compositing task. You'll see examples of sky replacements that don't work, and then learn how to create ones that do. Get a photographer's insight on masking, lighting, and blending adjustments naturally into the background of an existing photo.
- Masking, lighting, and perspective
- Correcting a blown-out sky with HDR exposures
- Shooting replacement images
- Using masks, blend modes, and adjustments layers