Why sky is the easiest thing to extend — and the easiest to get wrong
Sky has no hard edges, so any texture-based fill can continue it. The usual failure is colour: skies get darker or lighter towards the top, and a fill that copies a lighter patch from lower down leaves a visible band where the new sky starts.
ExtendPhoto continues the sky from the colour at the edge, then measures any brightness step across the join and evens it out (Seam match, on by default). Clouds are copied from the photo's own clouds, so they keep their softness.
Also good for
Ceilings and plain walls above a subject, studio backdrops, water and sand below a horizon (pull the bottom handle instead).













