White balance

White balance is how a camera or render engine compensates for the color of the light in a scene. Our eyes do this without thinking: a sheet of paper looks white under a tungsten bulb and in daylight alike. A camera has no such instinct, so without adjustment warm light pushes the image towards orange and shade or overcast sky pushes it towards blue.

White balance in rendering

In physically based render engines, lights are given a color temperature in kelvin, and the camera’s white balance uses the same scale. Balancing the camera to the main light source keeps white surfaces neutral under that light. Keeping the camera slightly warm in an early-evening interior gives a cosy mood, whereas neutralizing it completely can drain the atmosphere out of the scene. The choice is as much about storytelling as it is about accuracy.

Mixed lighting

With mixed light, such as a living room with daylight from the windows and warm downlights inside, there is no single correct value. The usual approach is to balance for the dominant source and let the others keep some color, which adds depth. Neutral walls matter more than they seem: a wall that drifts too yellow or too blue makes clients misjudge paint, stone and timber colors. For more ways to make an interior read as real, see how to get a realistic interior render.