what is lumen

what is lumen

What is lumen?It is the unit used to measure brightness of any source of light. The higher the lumen the brighter the source of light, in this case the projector. ANSI lumen is the industrial term for the amount of light. A candle emits approximately 12.5 lumen.

The average amount of light from a lamp projector is 2000 lumen. However, on our previous article on how high-tech  laser projectors work, we saw that a laser project emits at least 3500 lux. Their brightness remains constant for a very long period of time.  In our discussion on how modern LED projectors work, we discovered they are offer high level of brightly but wear out with time.

For comparison purposes, here are some of the common light source you know about and the amount of light they require.

Area Lumens/Sq M
Kitchen 300-400
Kitchen (Task) 700-800
Living Room 400-500
Hallway 300
Bedroom 300-400
Bedroom (Task) 700-800
Bathroom 500-600
Bathroom (Task) 700-800
Reading Area 400

The type of task you are performing determine the amount of light you need.  While the lumen describes the brightness of a light source, the watts do not.  Watts describes the amount of energy that light source is using to give what brightness it is emitting. This is a 5 w LED bulb is able to give as much amount of light as 50 filament bulb.

Lumen is also used to determine projector out.  Do you know there are projectors  for daylight use?  They are able to output incredibly huge amount of light.   For a projector to qualify for day light use, it must be capable of emitting 3500 lux. This is equivalent to  280 candles in the same room.