In this tutorial we’re going to look at replacing the sky in Photoshop. It’s always annoying when you’ve got an image that you like, but the sky is flat and dull, to the point where it may be ruining the shot. We’re going to look at a quick and easy way to rectify the situation.
Choosing the right photo
This technique will work with the majority of shots, but there are a few types that you might want to avoid. If you had a landscape photograph of a lake for example, this may look unrealistic if you add a new sky with clouds and these are not reflected in the lake.
It would be possible to add these too, but it can be difficult to get exactly right. Similarly, if you have a cityscape with a very detailed and varied skyline, this can also prove difficult when it comes to accurately adding the new sky.
Below is the image I’ve chosen, a wooden boat resting on a shingle beach. Many of the skies you might want to replace may be grey/white and washed-out, this image has a nice blue sky, but there is no cloud, and therefore no detail and contrast in the sky. It’s just too boring for my liking. A nice blue sky with some fluffy cloud will improve the shot.
Below is the final image that we’re going to work towards:
Choosing the new sky
For this I have my own archive of sky images that I’ve taken over the years, so it’s easy for me to find a suitable one to use. You may not have that luxury, so see if you can find a suitable one online, sxc.hu could be a good place to look (all images from there are free). Below is the sky I’ve chosen to use:
Removing the old sky
Open the image you’re going to work with in Photoshop, double click the background layer to turn it into a regular layer. As the sky is made of similar blue tones I’m going to select it using the magic wand tool, the perfect choice for this type of selection. You can set a specific tolerance for the magic wand tool, for this image I used 25, and then held down the shift key to add the varying blue tones of the sky to the selection.
This does a great job of the selection, but hasn’t picked up the tiny thin areas between the boat mast. To get these too, I went to the main menu at the top and chose Select > Similar, this does exactly what it says on the tin and has picked up the tricky areas between the boat mast perfectly. I then enter quick mask mode (press ‘Q’ on your keyboard to do so) to check the selection, see screenshot below:
With just a few seconds of using the magic wand tool I have a near perfect selection. Although, the eagle-eyed among you will notice a slight problem, when I used the Select > Similar command, I inadvertently also selected the sea on the right of boat.
Clearly we don’t want to replace the sea, so just paint that back in using the brush tool from within quick mask mode (make sure your foreground colour is black to do so). Have a good check that the rest of the selection edge is perfect, touch up if necessary.
We then exit quick mask mode (by pressing ‘Q’ again), and then delete the sky now that we’re happy with the selection.
Adding the new sky
Open your new sky image in Photoshop and set the width as the same as your target image, (it could be left bigger if you want to crop it of course). Select all, then paste into our main document. Drag the sky so it becomes the bottom layer so it sits behind our foreground and position to your liking. Let’s have another look at the final image:
Replacing the sky in Photoshop can make such a difference to an image, it’s a technique that’s definitely worth knowing. And also a nice quick technique, providing your original image isn’t too complex. Below are before and after shots of another sky replacement I did recently, this time adding a slightly more dramatic feel to the image.