How To Relight Photos & Change Time Of Day With AI

The Problem

Great shot, wrong lighting. You nailed the composition and moment, but it's flat midday sun that washes everything out. Traditionally you'd reshoot (expensive, often impossible) or spend hours in Photoshop (tedious, requires skill).

AI-powered relighting tools can now fundamentally transform lighting conditions - not just tweaking brightness, but simulating what the scene would look like shot during golden hour or in a studio. And they preserve faces remarkably well.

I've tested these tools extensively. Here's what actually works. For more AI tools that impact creative workflows, check out my top AI tools roundup.

Flux Kontext: My Go-To for Relighting

Flux Kontext from Black Forest Labs uses "in-context image generation" - it understands your existing image and makes targeted modifications rather than regenerating everything (which older tools did, often butchering faces).

Three models available: Kontext Dev (open-weights, runs on consumer hardware), Kontext Pro (fast iterative editing), and Kontext Max (maximum quality). For relighting, Pro hits the sweet spot. Most edits complete in 15-45 seconds.

I use the BFL Playground for testing - direct access to all models, plus I can create API keys for integration into other apps.

Prompts like "golden hour lighting, evening photoshoot" or "warm sunset illumination, soft shadows" work well. Be descriptive about lighting quality, not just time of day.

Before & After: Midday to Golden Hour

Original - flat lighting

After - golden hour transformation

Faces stay intact - same expressions, features, identity. The AI adds warm light naturally, creates appropriate shadows, shifts color temperature without looking over-processed.

Prompting Strategies

Structure: [Lighting Quality] + [Time/Atmosphere] + [Technical Details]

Effective Prompts

• Golden Hour: "golden hour lighting, warm evening sunlight, soft directional light from the side"
• Dramatic: "dramatic chiaroscuro lighting, strong contrast, deep shadows, cinematic"
• Studio: "professional studio lighting, soft diffused key light, subtle fill"
• Twilight: "blue hour atmosphere, cool twilight lighting, ambient glow"

What doesn't work: vague prompts like "better lighting." Describe what you DO want, not what you don't want.

Proposal Scene: Evening Romance

Original lighting

Golden hour romance

Open Source Alternatives

IC-Light

IC-Light (Imposing Consistent Light) is open-source, built on Stable Diffusion. Uses "consistency constraints" during training so lighting changes look physically plausible rather than just color-shifted.

Try it at iclightai.com or install locally with a capable GPU. Specify lighting direction (left, right, top, bottom) plus text prompts.

Other Options

• Krea AI Relight - Free, easy to use. Good for quick experiments.
• Clipdrop Relight - Manipulate light source positions directly, like placing virtual studio lights.
• ComfyUI + ControlNet - Maximum control, more technical setup.
• AI HomeDesign Day to Dusk - Specifically for real estate photography time-of-day changes.

Garden Portrait: Flat to Warm

Original - overcast/flat

After - warm directional light

When To Use AI Relighting

• Salvaging bad lighting: Great moment, unfavorable light - rescue it.
• Consistent series: Normalize lighting across shots from different times/locations.
• E-commerce: Products shot under inconsistent lighting matched to studio look.
• Real estate: Daytime exteriors to dusk for emotional impact.

At MuseMouth, I help businesses identify where AI tools can slot into existing processes without sacrificing quality.

Limitations

• Complex multi-light scenes: Five different colored lights from different angles will confuse most tools.
• Extreme transformations: Harsh noon to candlelit dinner can look artificial. Moderate changes are more reliable.
• Physical accuracy: AI simulates lighting, doesn't calculate physics. For critical color accuracy, traditional methods win.
• Batch consistency: Individual results impress, but hundreds of perfectly consistent images still needs manual refinement.
• Color grading: Flux can do color grading, but it's a crapshoot if you need fine control. You might get something close to what you want, or something completely different. For precise color work, stick with Lightroom or DaVinci Resolve.

AI relighting is one tool in your arsenal, not a replacement for photography fundamentals. For more on AI tool selection, see my nano-banana image generation review.

Getting Started

1. Free first: Krea AI or IC Light AI to understand what's possible.
2. Then Flux: BFL Playground for serious work.
3. Local deployment: If processing high volumes, set up Stable Diffusion with IC-Light for unlimited usage.

Bottom Line

AI photo relighting has crossed from experiment to practical tool. Flux Kontext delivers results that would have required expensive reshoots or hours of Photoshop work a year ago.

AI doesn't replace good photography - it gives you options you didn't have before. That shot ruined when a cloud passed over? Recoverable. Client wants "warmer, more romantic"? Minutes instead of hours.