What each part of the prompt does
- Edit, not regenerate
- "Change only the light and colour" tells Gemini this is an edit, not a new image. Listing "person, pose, clothes and background" closes off every other part it might be tempted to redraw.
- Light direction
- "Low sunlight from the left with soft shadows falling to the right" gives a direction and the matching shadow. If the background in your photo already has shadows going the other way, swap left and right.
- Rim light
- A warm rim on the hair and shoulders is the detail that separates the person from the background at golden hour, and it is what viewers notice even when they cannot name it.
- Grade and skin
- A slightly warmer, richer grade handles the overall colour, while "keep the skin texture natural" protects against the waxy look that strong warm grading can cause.
Variations to try
Same idea, one thing changed. These have no example image yet.
Sun from the right Relight my uploaded photo as if it was taken at golden hour. Keep the person, pose, clothes and background exactly the same; change only the light and colour. Add warm, low sunlight from the right with soft shadows falling to the left, a gentle warm rim light on the hair and shoulders, and a slightly warmer, richer colour grade. Keep the skin texture natural. Same framing as the original.
Blue hour Relight my uploaded photo as if it was taken at blue hour, just after sunset. Keep the person, pose, clothes and background exactly the same; change only the light and colour. Add cool, soft blue ambient light across the scene, a small warm glow on one side of the face from a nearby street lamp, and a deeper, calmer colour grade. Keep the skin texture natural. Same framing as the original.
Indoor window light Relight my uploaded photo as if it was lit by a large window in the late afternoon. Keep the person, pose, clothes and background exactly the same; change only the light and colour. Add warm, soft window light from the left with gentle shadows falling to the right, a faint warm highlight on the hair, and a slightly warmer colour grade. Keep the skin texture natural. Same framing as the original.
If the result isn't right
- If Gemini swaps in a sunset sky or a new background, reply "keep the original background exactly; only the light on it changes".
- When everything turns orange, ask for "subtler warmth, keep whites slightly warm but still white".
- If the photo gets cropped or zoomed, add "output the full original frame, nothing cropped".
- Face shadows pointing the wrong way look fake; say "shadows on the face fall to the right, matching the sun on the left".

