Chobial
Photography basics

White balance: why photos turn orange or blue

Lesson 5 of 8

Take a photo indoors at night and it often comes out orange. Take one in the shade on a sunny day and it looks cold and blue. Nothing is broken: that's the colour the light really was. White balance is how a camera decides what to do about it.

The idea

Light comes in different colours. Candles and old light bulbs give warm, orange light. Midday sun is close to neutral. Shade and overcast skies are lit mostly by blue sky, so they're cool. Your brain adjusts for this without you noticing, so a white page looks white to you under any of them. A camera has to be told, or guess.

That colour is measured as a colour temperature, in kelvin (K). Low numbers are warm, high numbers are cool:

2500 K320045005500650010000 K Candle, bulbsSunrise, sunsetMidday sunOvercastOpen shade Set the camera to the light's number and the light looks neutral.
The kelvin you set describes the light, so the camera can cancel it out.

When you set white balance, you tell the camera what colour the light is, and it adds the opposite to cancel it. Tell it the light is 3200 K (warm bulbs) and it adds blue. That's why the numbers feel backwards at first: a lower setting makes the photo cooler.

Neutral isn't always right

Auto white balance tries to make everything neutral, and that's not always what you want. A sunset corrected to neutral loses its gold. A candlelit dinner corrected to neutral looks like an office. Often the best white balance keeps a little of the light's real colour, because that colour is part of the mood.

In Chobial

  1. Open the controls and tap WB.
  2. Pick Auto, or a preset for the light you're in: Daylight, Cloudy, Shade, Tungsten (warm bulbs) or Fluorescent.
  3. Or pick Kelvin and set it yourself, from 2500 K to 10000 K.
  4. For exact colour, tap GREY CARD, then tap something neutral in the frame: a grey card, a white wall, a sheet of paper. Chobial measures the light from it.

Because every photo is a RAW, none of this is final. In the editor, the Color tool has Temperature and Tint, and changing them works as if you'd set them when shooting.

Auto can flicker between shots. When you take a series in the same light, such as a room or a portrait session, a preset or a Kelvin value keeps the colour the same from photo to photo. Auto may shift it every time the framing changes.

Feel the scale

  1. At home in the evening, with warm lamps on, point the camera at a white wall or a sheet of paper.
  2. Tap WB and choose Daylight. The paper goes orange: that's the true colour of your lamps.
  3. Choose Tungsten. The paper goes nearly white.
  4. Choose Kelvin and drag slowly from 2500 to 5000 K, watching the paper. Find the number where it's white, then go a few hundred higher and see how much warmth you want to keep.
  5. Finally, try GREY CARD and tap the paper. Compare where it landed with your guess.

Films change colour on purpose, too: a warm film on top of neutral white balance is how many classic looks are built. Try a few in making iPhone photos look like film.

Next: focus, and getting the right thing sharp.

Questions

Why does a lower Kelvin number make my photo bluer?

Because the setting describes the light, not the look. Setting 3000 K tells the camera the light is warm and orange, so it adds blue to cancel it out. If the light was actually daylight, that blue is left over.

Can I fix white balance after taking the photo?

Yes. Chobial shoots RAW, so white balance isn't baked in. Use Temperature and Tint in the editor's Color tool. A mask can even set a different white balance for one part of the photo.

What's tint?

The other direction colour casts go: green to magenta. Fluorescent and some LED lights add a green cast that temperature alone can't fix. Tint moves the colour toward magenta to cancel it.