White balance: what it is and how it affects the clinical photo
Quick facts
- Definition
- Adjustment that makes the camera interpret white as white under a specific light.
- Measures
- Color temperature of the light, in kelvin, and tint.
- Effect
- Changes the skin tone and can give a false impression of redness or pallor.
- To compare
- Keep the same setting and the same light in the before and after photos.
- In the clinic
- A neutral wall and fixed light help more than filters.
White balance is the adjustment the camera makes so that white objects look white, whatever the light. The yellowish light of a lamp, the bluish light of a window or the cold light of an LED change the color of the scene, and white balance compensates for that change.
Why does this matter in a clinical photo?
Skin tone, redness, yellowing and spots depend on the color of the light. Two photos of the same patient with different white balances seem to show different skins, and this gets in the way of comparing before and after. A bruise or erythema can look worse or better just because of the light.
| Light | Common effect on skin |
|---|---|
| Warm lamp | Yellowish or orange tone |
| Window without direct sun | Bluer tone |
| Cool LED | Pale skin |
| Diffuse light, constant | More faithful color |
How to standardize?
- Always photograph in the same place, with the same light and the same distance.
- Lock the white balance manually, when the camera allows it, or use a neutral reference.
- Avoid filters and beauty modes, which change color and texture.
- Keep the focal length and the head position the same, as in the standard views of the face.
And in AI-generated images?
The color of a generated image depends on what the model receives. An original photo with an odd tone tends to generate a projection with the same tone. When presenting to the patient, it is worth starting from a well-lit photo.
Also called: white balance, color balance.
Frequently asked questions
Why does skin tone change from one photo to another?
Almost always because of differences in light and white balance between the photos. Photos taken in different places or at different times can show different tones for the same skin.