Useful information about bulbs When buying a new LED bulb, there are some important things to be aware of. The brightness of an LED bulb is measured in what is called lumen instead of watt.
15W = 140 lumens
25W = 250 lumens
40W = 470 lumens
60W = 800 lumens
75W = 1050 lumens
100W = 1520 lumens
In addition, a RA- or CRI-value is also stated on the bulb. It describes the light's ability to reproduce colours and is assessed on a scale of 0-100 CRI, where 100 CRI corresponds to daylight. For an ordinary home, it is recommended that you use a bulb with a CRI value of min. 80CRI.
The Kelvin rating, on the other hand, describes how warm the light from the bulb is.
8,500 - 10,000 K = Cool blue
7,000 - 8,500 K = Cool white/blue
4,500 - 7,000 K = Cool white
3,000 - 4,500 K = Neutral white
1,000 - 3,000 K = Warm white
In comparison, the light from a candle has a chelvin level of approximately 1,500 K, direct sunlight is 5,500 K, while the blue sky reaches 10,000 K.