How to Write AI VFX Prompts for Glow and Light Rays

God rays, lens flares, and ambient glows are among the most-used light effects in cinematic editing — and among the most abused. A well-crafted light ray prompt adds depth and dimensionality. A vague one produces a generic digital bloom that reads as an effect rather than a light source. Here's the difference.

Light ray effects require two things to look real: a light source that justifies the ray's existence, and a medium for the rays to be visible in (dust particles, fog, mist, atmospheric haze). Rays in perfectly clean air are invisible. Always describe what the light is travelling through.

Glow effects work differently — they describe the ambient emission of light from a surface or object, rather than directional shafts. A screen glow, a neon sign's spill, an energy orb casting coloured light — these are glow prompts, not ray prompts. The vocabulary distinction helps the AI generate the right type of light effect.

What FXbuddy needs in a glow or light ray prompt

• Light source: sun, practical lamp, neon sign, fire, screen, magic effect, headlights
• Source position: upper left, behind subject, low on horizon, off-camera right
• Medium (for rays): dust motes, fog, forest canopy particles, smoke, mist
• Colour temperature: warm gold, cool blue, orange sunset, white clinical, neon pink
• Intensity: subtle ambient glow, moderate soft rays, dramatic hard shafts, blinding flare

5 example prompts you can copy

Common mistakes

• No medium for the rays: "Add light rays" in a scene with no dust, fog, or particles described produces a digital-looking beam rather than a physical one. Always pair light rays with something for the light to scatter off.
• Forgetting the source position: Rays need to emanate from somewhere. Without a source direction, the AI places them arbitrarily. Specify "from upper left," "from behind the subject," "through the window at camera right."
• Overdriving the intensity: Very bright flares and rays can wash out your subject. If you want subtle enhancement, add "subtle" or "restrained" as qualifiers rather than defaulting to the AI's tendency toward dramatic effects.
• Conflating glow and rays: "Add a glow and rays" can confuse the output. If you want both, describe them as separate elements: "soft ambient blue glow from the screen, plus a single volumetric shaft from the window."

Tips for better glow and light ray results

• The most cinematic light rays have visible texture — "dust motes floating in the shaft" or "particles of pollen visible in the beam" elevate generic rays to something memorable.
• For sunset shots, the best prompt combines a low horizon sun, atmospheric haze, and a specific orange-pink-amber palette. All three together create the look; any two alone produce something generic.
• Specify whether you want a natural or a cinematic/stylised lens flare. Real lens flares are complex. Anamorphic flares are horizontal and blue. Vintage lens flares have warm green and orange. The AI recognises these distinctions.
• For neon night shoots, list the practical light sources in the scene and their colours before requesting glow — "red neon sign at top left, white fluorescent from behind, orange street lamp at distance. add soft spill from all three onto the subject and ground."
• Light rays going through fog look better than fog alone. If you've already generated fog for a shot, layer a light ray prompt on top for a significant visual upgrade.

Frequently asked questions

How do I add god rays or volumetric light shafts to a clip?

Describe the light source, its position, and what the shafts pass through: "golden god rays streaming through the forest canopy from the upper right, shafts of light hitting the ground and catching dust particles." The AI needs both the light source position and a medium for the rays to be visible in — dust, fog, or mist in the air.

Can I add a glow effect around a subject or object?

Yes. Describe the glow colour, intensity, and what it radiates from: "soft warm gold aura around the subject, brightest at the outline, fading into the background." For object glows: "blue ambient glow emanating from the screen in the background, casting colour onto nearby surfaces."

What is the difference between a lens flare and a light ray prompt?

A lens flare is a camera-optics artefact — it appears on the lens, moves with camera movement, and creates geometric flare artifacts. A light ray is a physical atmospheric phenomenon — shafts of light made visible by particles in the air. Use "lens flare" for the camera-optics look, "god rays" or "volumetric light shafts" for the atmospheric look.

How do I make a sunrise or sunset glow look more dramatic?

Combine light source position, colour temperature, and atmospheric diffusion: "sun positioned low in the upper right, deep orange-pink light bleeding across the horizon, atmospheric haze softening distant elements, long shadows from foreground objects." The combination of warm colour, low angle, and atmospheric diffusion creates the most dramatic looks.

Related prompt guides

Also see the AI Scene Relighting effect page for a full workflow that covers light direction changes.