What is 500 lumens?
This is the light intensity uniformly distributed over a solid angle of a steradian and his luminous flux total emitted in this direction is called Lumen. A simpler way to define Lumen would be to say that it is of the total amount of visible light in a direction or angle projected onto a surface . It is also measured in candle , which is the luminous flux emitted by one candela under a solid angle without losses (isotropic form) of 4·π , which is the radius of a sphere squared, or:
I v (candle) × Ω (steradian) = Φ v (lumen) = E v (lux) xm 2
Lumen Equivalence Table
For example, a 100W incandescent bulb produces 1,000 to 1,200 Lumens. The values given below are Watts to Lumen equivalents for LED bulbs and serve as a guide, there may sometimes be small variations:
LED bulb |
Lumen equivalent |
incandescent, halogen and PAR |
|---|---|---|
| 1W | 70-100lm | 10W |
| 1X3W | 180-250m | 15W |
| 3X1W | 200-280lm | 25W |
| 4W | 300-360lm | 35W |
| 5W | 380-450lm | 35-45W |
| 6W | 450-520lm | 40W |
| 7W | 500-620lm | 45W-60W |
| 9W | 700-850lm | 50W-80W |
| 10W | 800-980lm | 60W-70W |
| 12W | 900-1000lm | 80-100W |
| 14W | 1000-1200lm | 110W |
| 15W | 1100-1300lm | 60W-120W |
| 18W | 1250-1500lm | 140W |
| 24W | 1800-2100lm | 165W |
| 30W | 2300-2750lm | 200W |
| 40W | 3000-3600lm | 120W-270W |
| 45W | 3500-4200lm | 150W-300W |
| 50W | 4500-5000lm | 250W |
| 70W | 6300-7000lm | 400W |
| 80W | 6400-7200lm | 500W |
Some differences
However, LED bulbs may have a small "handicap" for some applications, they emit their light in one direction only (full angle) unlike fluorescent tubes, which emit light in all directions. It is therefore often necessary to equip the light source with a reflector system, which is generally linked to low losses. But on the contrary, it can also be an advantage, if a fluorescent tube is replaced by a T8 LED tube, this reflector will not be necessary and therefore no losses will be generated. In any case, Lumens are a good reference to consider when purchasing and replacing incandescent bulbs with LED bulbs .
Watts vs. Lumens
A few days ago we could say that watts were a good unit of measurement for incandescent bulbs. But there are several reasons why it is no longer interesting to continue using Watts. Let's suppose a 40 W bulb, which normally produces 400 lm if we buy it with all the other light sources such as halogen, fluorescent, low consumption and LED, all produce much more lumens than 1 W and therefore have a higher yield, which makes no sense. continue to use the same factor scale.