In this 9-minute video tutorial from Serge Ramelli, learn how to easily swap out an unattractive white sky from a photo for a more dramatic one using Photoshop. Utilizing the power of the multiply blend mode, it’s possible to convincingly change the sky in the shot in minutes.
First, open up your alternative sky in a layer on top of your target photo. Position it where you want to swap it in, right on the horizon, and duplicate it. Flip it vertically, and drag it underneath the first sky to create a “perfect mirror” of the sky.
Then merge the layers, and apply the multiply mode to the shot. It will immediately swap the sky into the shot, even giving a reflection on the foreground.
There are some imperfections, such as (in this photo) the Eiffel Tower having some clouds embedded into the structure, but it’s a minor detail that can be ironed out with some further tweaks.
Making a rough selection of the foreground, Ramelli feathers the selection and makes an extreme Gaussian Blur of the sky layer, removing the absolute mirror reflection from the scene. This gives a much softer, and much more realistic, reflection to the scene.
Creating a mask, you can easily brush away the sky from structures and other areas you don’t want it to be blended into.