Most bad hand analyses are not a technical problem - they are a photo problem. Here is how to take a photo that gives the model what it needs, in under two minutes.
Light is everything
Use daylight, not a flash. Overhead light flattens creases; side light makes them visible. Stand near a window, hold your hand at a slight angle and watch how the lines appear.
Background and position
- Plain, single-colour background - a sheet of paper or a neutral table.
- Palm facing up, fingers relaxed and slightly spread - not stretched.
- Whole hand in frame: wrist, palm and all fingertips.
- No rings or jewellery; they confuse the landmark detection.
Camera angle
Shoot from straight above, parallel to the palm. A tilted camera shortens fingers and distorts ratios. If your phone has a grid, use it to keep the hand centred.
Common mistakes
- Too dark or flashed: fine lines disappear, the model struggles.
- Hand cut off: missing fingertips or wrist means missing measurements.
- Verkrampfte Hand: spread fingers change the gaps.
- HEIC instead of JPG: many browsers cannot read iPhone HEIC files - export as JPG or use a screenshot.
Checklist before you upload
- Daylight, side light, no flash.
- Plain background, whole hand visible.
- Palm up, fingers relaxed.
- JPG or PNG file.
Then head to the free hand check - the model loads on the first step and runs entirely in your browser. If the tool warns about blur, tilt or a cut-off hand, retake the photo; the numbers get better with every good shot. More background: methodology and the basics.