What is colour temperature, and why does it matter when choosing a torch?

What is colour temperature?

Colour temperature (in full, Correlated Color Temperature or CCT) is a property of visible light that tells you whether the light feels "cool" or "warm". It is measured in kelvin (K). Cooler light looks bluish white, warmer light looks yellowish orange.

What does colour temperature mean in practice?

Different colour temperatures suit different jobs. The scale runs from warm yellow all the way to cool blue:

Categories for torches

Torch colour temperatures are tuned for different tasks, roughly in these categories:

1. Daylight white (5000K or more)
   Ideal for outdoor activities and search and rescue work, where you need strong, bluish white light.
   Downside: It can strain your eyes, and colours look less natural.

2. Cool white (about 4000K)
   Closer to natural daylight, so it's ideal for photography or precision work.
   Downside: It can be slightly hard on the eyes over long use.

3. Soft white (about 3000K)
   A gentle, yellowish white light that makes a pleasant, inviting atmosphere.

4. Warm white (about 2700K)
   Orange-tinted, perfect indoors, where it gives a friendly atmosphere.

In the picture below you can compare the colour temperatures of different torches:

Here's an example of how different light changes its surroundings: three light sources with different colour temperatures on the same bunch of flowers. Watch how the mood and the colours change:

Once you understand colour temperature, it's much easier to pick the right light for the place and the job. And if you're into torch tests, subscribe to my channel, you'll find plenty more there!