How to change the sky in a photo
Sky Replacement in Paint by Zaweba mattes the old sky, then lets you shift, scale, flip and relight a new one with a live preview, all as layers.
Open the photo in Paint by Zaweba and choose Edit > Sky Replacement. It finds the existing sky with a classic matte, then lets you pick a new sky and move, scale, flip and relight it with a live preview. The result is a group of layers, so the new sky and the colour change it makes to the landscape both stay editable.
Changing the sky is a classic fix for a dull day. A grey, blown out sky makes a good scene look flat, and a different sky can change the mood of the whole picture. The hard part is the edge, where trees and rooftops meet the sky, and that's what the matte is for.
What you need
A photo whose sky you want to replace, and a sky photo of your own to put in. Your own sky shots are best, ideally taken at a similar time of day and from a similar height. Paint by Zaweba runs offline on Windows, so all of this happens on your PC without uploading anything.
How the matte works
The sky matte looks for an area that is bright, smooth and connected to the top of the frame, then uses a guided filter to make the edge follow fine detail. This is a classical method, not an online AI. It works well on most daylight landscapes and less well on dark or very colourful skies, where the brightness rule doesn't hold.
Step by step
Choose Edit > Sky Replacement and pick your new sky. The preview updates as you work.
Start with placement. Move and scale the sky until the horizon and the light make sense. If the sun in the new sky is on the wrong side compared with the shadows in the landscape, flip it. That one setting fixes the most common giveaway.
Next, the edge. Shift the edge to push the matte in or out, and fade it to soften the join. Look closely at tree tops and thin branches, because they're where a halo or a gap shows first.
Then match the light. Adjust the sky's brightness so it sits right with the land, and use foreground lighting to bring the colour of the new sky onto the landscape. A warm evening sky over a cold, blue foreground never looks right, and this step is what makes the two belong together.
Press OK. You get a group containing a masked White Balance layer, which carries the lighting change to the foreground, and the masked sky itself.
Refining afterwards
Because the result is layers, you can keep working. Paint on the sky's mask to put back a chimney or a branch the matte took away. Lower the White Balance layer's opacity if the foreground tint is too strong. Move the sky layer a little if the composition still feels off.
Getting a good result
Match the direction of light first, then the colour, then the brightness. Keep the new sky believable for the lens: a dramatic wide sky dropped into a tight telephoto shot looks wrong. Watch water and windows too. A lake that still reflects the old grey sky gives the game away, so you may need to tint or retouch the reflection to match.
When to just improve the sky instead
Sometimes the original sky only needs help. Select > Sky makes a selection of the existing sky, and an adjustment layer through it can add contrast or colour without replacing anything. Try that first if the clouds are there but faint. When the sky really is blank, Paint by Zaweba's Sky Replacement is the quicker road to a new one.
