So you’re going to buy a LED light and the salesman is quoting some big numbers regarding the lumen output. Don’t be fooled… What you may be hearing is the ‘RAW’ or ‘Theoretical’ lumen output of the LED light as opposed to the more realistic ‘Effective’ lumen output. 


So what’s the difference you ask…..?


RAW or Theoretical lumens are the number of LED’s in a light multiplied by their maximum output rating. So if your light has 10 LED’s that have a maximum lumen output of 100 each than you would have 1000 lumens total. 


What can affect this lumen output? Well many things for example, heat, the amount of current used to drive the LED’s, lenses and reflector optics to name a few. 


The ‘Effective’ lumen output is a more realistic number that takes these factors into consideration and photometric testing has been carried out to measure this output. 


So when you are trying to compare LED lights to purchase make sure you are comparing the same light output in either Theoretical or Effective lumens