Colour temperature is the single most useful number on a lamp box, and the one most often ignored in favour of brightness.
What the numbers mean
- 2700–3000K — warm, incandescent-like. Best after sunset; least disruptive to sleep.
- 3500–4000K — neutral. Good for focused desk work during the day.
- 5000–6500K — cool daylight. Useful for detail work, harsh in the evening.
Why daylight is a bad default
Blue-rich light in the evening suppresses melatonin and makes the last hour before bed feel like the middle of the afternoon. If you work at 10pm, a 6000K lamp is actively working against you.
The practical setup
A lamp with adjustable temperature beats a fixed one, because the right answer changes with the hour. If you only buy one lamp: 3000K, dimmable, with the light reaching the desk and not your eyes.
Brightness matters too
For desk work, aim for roughly 300–500 lux at the surface. Too dim causes strain; too bright causes glare. A dimmer is more useful than a higher maximum.
Placement
Put the lamp on the opposite side from your writing hand so your shadow does not fall on the page. Aim the shade slightly away from you; bounce beats direct glare.
What we sell
The Compact Desk Lamp is 2700–5000K adjustable with three presets and a USB port. It is not the brightest lamp we tested; it is the one we kept using.