Required — image will be rejected without these

• iPhone 12 or newer Use the front-facing (selfie) camera — tap "Capture face" above
• Indoor, well-lit room No direct sunlight through a window; no dim or candle-lit rooms
• Face forward, eyes on screen Look directly at the front camera — no side angles
• Face fills 50%+ of the frame Move the phone close — forehead to chin should fill most of the screen
• Neutral expression Mouth closed, eyes open naturally — no squinting or smiling
• No flash Turn off flash — it washes out skin colour and breaks the calibration

Recommended — improves data quality

• Remove glasses Frames and reflections interfere with skin detection
• Hair away from face Especially the cheek and forehead area
• Capture in 2–3 rooms Different light sources per person improves model diversity
• Different people, not the same person We need variety — aim for a range of skin tones