Does FXbuddy sky replacement work on moving camera clips?

Yes. FXbuddy's AI engine generates sky replacements that are temporally consistent across the clip, including clips with camera movement. The new sky tracks the camera motion so it doesn't appear to float or drift. For very fast panning shots, results may vary depending on how much of the clip's composition changes between frames.

How do I prompt for a sky that matches a specific time of day?

Describe the sun position and colour temperature: 'replace sky with a golden hour sunset sky — sun low on the right horizon, deep orange and pink clouds, warm light on the horizon line.' Adding the sun's position helps the AI calculate how the new sky's light should interact with the foreground elements visible in your clip.

Can I use sky replacement to make a day shot look like night?

You can replace the sky with a night sky, but the foreground lighting from the original clip will remain daytime unless you also run a relighting pass. Sky replacement alone changes the sky — not the light on subjects and surfaces. For a convincing day-for-night conversion, use sky replacement plus a relighting prompt to push the foreground into matching cool moonlit or artificial light.

What kinds of skies work best for sky replacement?

Dramatic skies with visible features — clouds, sun position, colour gradients, atmospheric phenomena — produce the best results because the AI has more visual information to generate. Flat featureless skies (pure blue or pure grey) work fine but may look less interesting than skies with weather elements or lighting events.

How to Write AI VFX Prompts for Sky Replacement

Sky replacement is one of the most-used effects in FXbuddy — it turns grey overcast B-roll into usable footage, fixes continuity problems between clips, and establishes time of day without a reshoot. A good sky prompt describes the sky you want, not just the sky to replace.

The most common mistake in sky replacement prompts is describing the problem rather than the solution. "Replace the grey sky with something better" is not useful. "Replace the grey overcast sky with a dramatic late afternoon storm sky — dark rolling clouds, visible sun break at the horizon right, shafts of light breaking through" gives the AI a clear visual target.

Sky replacement in FXbuddy generates the new sky as part of a temporally consistent clip output, meaning it holds across the full duration of your footage. It's not a frame-by-frame mask — it's an AI-generated sky integrated with your clip at generation time.

What FXbuddy needs in a sky replacement prompt

Sky type: golden hour, storm clouds, overcast blue, night stars, sunrise, sunset, dramatic cumulus
Sun/moon position: low on the right horizon, directly overhead, behind clouds, fully set
Colour palette: warm orange-amber, deep pink and purple, cool steel-grey, pale winter white
Weather elements: cloud type (cumulus, cirrus, cumulonimbus), storm activity, clearing weather
Horizon transition: how the sky meets the treeline, roofline, or horizon in your clip

5 example prompts you can copy

replace the overcast grey sky with a dramatic golden hour sunset. sun low on the right horizon. deep orange and amber cloud edges. pink upper atmosphere. warm light bleeding into the cloud base.

swap the flat white sky with a severe storm system approaching from the left. dark grey-black cumulonimbus clouds. lighter grey at the right horizon suggesting clearing. no rain yet — pre-storm tension.

replace the daytime sky with a clear night sky. stars visible, no moon. deep navy blue fading to near-black at the zenith. milky way subtly visible. cool ambient light from the starfield.

change the cloudy midday sky to a bright blue summer sky with scattered white cumulus. high cirrus at the top. warm white sunlight from a high angle. optimistic, open, commercial look.

replace the existing sky with a winter sunrise. very pale peach and lavender on the horizon. thin cloud streaks. no direct sun visible — diffused behind thin clouds. cold, quiet atmosphere. muted colours throughout.

Common mistakes

Not specifying the sun position: The sun position in the new sky affects how the AI renders the horizon transition and any light interaction with foreground elements. Always specify where the sun should be.
Forgetting the horizon zone: If your clip has a visible treeline, buildings, or other horizon elements, describe whether you want the sky to sit cleanly above them or bleed with atmospheric haze. "Sky meets the treeline with a slight golden mist" integrates better than a hard edge.
Unrealistic time-of-day pairings: Replacing a sky with "night stars" on a brightly lit daytime exterior will look wrong unless you also add a relighting pass to darken the foreground. Match the sky's implied light to the actual foreground lighting or plan a two-pass workflow.
Vague drama requests: "Make the sky more dramatic" isn't actionable. "Add dark storm clouds with visible lightning in the distance and a strong sun break at the lower right" is.

Tips for better sky replacement results

After sky replacement, run a relighting prompt to shift the foreground's colour temperature to match the new sky. The combination produces a coherent result rather than a composited look.
For wedding, commercial, or lifestyle footage, "soft blue sky with small white cumulus, sun slightly left of centre, gentle warmth" is almost always the right choice — dramatic enough to improve the shot without distracting from the subject.
Storm skies work particularly well for music videos and action sequences. Adding "visible but distant lightning strike in the background" to a storm prompt adds life without overwhelming the composition.
Twilight skies (post-sunset, pre-night) — deep blue-purple gradient with a thin warm band at the horizon — are among the most cinematic options and work on almost any exterior clip.
If your clip has lens flare from the original sun, mention the flare in your prompt: "new sky with sun in the same upper-left position as the original, with a soft lens flare from the sun maintained." This helps the AI preserve visual continuity with the original clip's camera response.

Frequently asked questions

Does FXbuddy sky replacement work on moving camera clips?: Yes. FXbuddy's AI engine generates sky replacements that are temporally consistent across the clip, including clips with camera movement. The new sky tracks the camera motion so it doesn't appear to float or drift. For very fast panning shots, results may vary depending on how much of the clip's composition changes between frames.
How do I prompt for a sky that matches a specific time of day?: Describe the sun position and colour temperature: "replace sky with a golden hour sunset sky — sun low on the right horizon, deep orange and pink clouds, warm light on the horizon line." Adding the sun's position helps the AI calculate how the new sky's light should interact with foreground elements in your clip.
Can I use sky replacement to make a day shot look like night?: You can replace the sky with a night sky, but the foreground lighting from the original clip will remain daytime unless you also run a relighting pass. For a convincing day-for-night conversion, use sky replacement plus a relighting prompt to push the foreground into matching cool moonlit or artificial light.
What kinds of skies work best for sky replacement?: Dramatic skies with visible features — clouds, sun position, colour gradients, atmospheric phenomena — produce the best results. Flat featureless skies work fine but may look less interesting than skies with weather elements or lighting events.

Related prompt guides

Relighting a Scene Prompts

Match the foreground lighting to your new sky.

Golden Hour Look Prompts

Get the full golden hour treatment — sky, light, and grade.

Weather Changes Prompts

Full weather transformations for exterior shots.

Also see the AI Sky Replacement effect page for a complete workflow walkthrough.

Try these prompts in your next edit

FXbuddy is a Premiere Pro and After Effects plugin. Paste any prompt above and the new sky drops onto your timeline in under 90 seconds.

Try FXbuddy today