In this tutorial, we’ll learn how to easily replace the sky in a photo.
We will use a the selection tool and a layer mask to separate the sky from the area below.
We will then use Advanced Blending sliders to replace the original sky with the new sky.
Open your two images in Photoshop.
For this tutorial we will be replacing the grey sky behind the house with a bright blue sky.
I have chosen this photo as it also has trees in the background.
We need to merge our images into one document. Drag the image of the sky onto the image of the house and in the Layers palette double-click on the background layer. This will unlock it and allow you to rename it. Name this layer ‘House’ and name the other layer ‘Sky’ and move it underneath your House layer.
Duplicate the House layer by right-clicking your mouse on the layer and selecting Duplicate Layer.
We don’t need the top House layer for now, so you can temporarily turn it off by clicking on the visibility icon (eyeball) to the left of the layer.
Select the House layer by clicking on it to make it active.
Now we are ready to select the area below the sky. Select your Polygon Lasso Tool and draw a selection outline around the area of the photo below the sky.
After selecting the area, we will want to use Photoshop’s Advanced Blending sliders to select and hide areas of an image based on their color, which means we should have no problem selecting and hiding the blue sky without affecting the green trees.
For this reason, we want to select all areas of the house but we can be fairly loose with the trees selection as long as you stay below any areas where the blue sky is showing through.
Convert the selected area into a layer mask. Click on the Layer Mask icon at the bottom of the Layers panel.
Select the House copy layer in the layers palette to make it the active layer and click the visibility icon (eyeball) to turn it back on. The entire original photo will now re-appear in the document window.
Right-click on the House copy layer in the Layers panel and select Blending Options. This opens Photoshop’s Layer Style dialogue box. Click on the ‘Blend If’ dialogue box and set the target colours to Blue.
Drag the top right slider towards the left. As you drag the slider, you’ll begin to see the original sky in the photo disappearing, revealing the replacement sky underneath. Drag until most of the original sky is gone.
The only problem now is that we’re seeing a lot of harsh edges and fringing around the trees. To fix that, we need to soften the transition between the two photos by splitting the slider in half. To do this, hold down the Alt key and click back on the slider and continue dragging towards the left. This will soften the edges. Click ‘okay’ and check to see if you are happy with your final image.