Lighting quality in a source photo has an outsized effect on AI transformation results, since it directly affects how clearly the model can read facial structure, skin tone, and fine detail.
Harsh shadows obscure real detail
Strong directional light (harsh overhead sun, a single close flash) creates deep shadows that can hide or distort facial features the model needs to accurately preserve — soft, diffuse light avoids this problem.
Backlighting is a common mistake
A subject lit from behind (standing in front of a bright window, for example) often ends up underexposed and detail-poor in the face — exactly the opposite of what a model needs for accurate preservation.
Natural daylight is usually the easiest good option
Indirect natural daylight — near a window but not directly backlit, or outdoors in open shade — reliably produces even, flattering, detail-rich lighting without needing any special equipment.
Is flash photography bad for AI transformation photos?
Direct on-camera flash tends to flatten features and create harsh shadows, similar to harsh overhead light — it's generally one of the less ideal lighting choices compared to soft natural or diffused light.