Lighting experts...

[jaytizzle]

I have a 90W LED fixture (45 each 1W white and 1W blue semileds). I was at a club meeting this weekend and a guy had a LUX meter on hand so we took some readings. The meter maxed at 2000 foot-candles and it was maxed out at 6" away from the light. We didn't have a PAR meter handy so there was no way to test the light output in the water column.

I'm not familiar at all with LUX. What does this value really mean, if anything?

FWIW ambient lighting in the room was about 20 foot-candles.

 

[jaytizzle]

Bump.. anybody?

 

[eggie]

Hey Jay here is a good page to learn the diffrence between LUX and PAR

Light and Plants

Just to explain a little lux is a measurement that the human eye could see but it captures more the yellow spectrum leaving out the blue and red spectrum

Wich in PAR is the light that corals or plant uses and capture the hole spectrum from 400 to 720 its called the Photosintetic Active Radiation (PAR)

Thats why a PAR meter is better then a LUX meter it picks up more light spectrum wich will increase your values

 

[jaytizzle]

Thanks, eggie! That source says that 1900 lux is considered to be high light and I exceeded that. Interesting... And it also makes sense that it only read about 450 with the blue lights on. That's because that meter doesn't measure the blue part of the spectrum extensively because it isn't of much interest to the human eye!

So I really need to get a PAR meter on this thing but from that lux reading I imagine that it will be pretty impressive for a 90W semiled fixture!!!