ChicagoReefs COMMUNITY PAR METER LOAN/RENTAL PROGRAM

Meter is checked back in and is in the same condition as post #7.

PMing next in line [MENTION=1125]ThePorkchopExpress[/MENTION]
 
Meter is checked back in and is in the same condition as post #7.

PMing next in line [MENTION=2740]willtheld[/MENTION]
 
Can I let the next person cut in front of me? I'm on tour with Carrie underwood till may 30th.


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Meter is checked back in and is in the same condition as post #7.

PMing next in line [MENTION=2740]willtheld[/MENTION]
 
Josh,

Is PAR/wattage output linear? For example, if a light is rated at 500 par 12" below the surface at 100% ouput, will tuning it down to 50% give you 250 par?
 
Paulip said:
Josh,

Is PAR/wattage output linear? For example, if a light is rated at 500 par 12" below the surface at 100% ouput, will tuning it down to 50% give you 250 par?
Click to expand...

No. Light has an inverse square with distance. You have a couple factors fighting you, one is resisatance. Your optics and the water column slow the light. Two is LEDs don't dim in a linear fashion, not to mention each led will dim differently than one made by a different company or in a different wavelenght. The only way to know par with an confidance is to measure.
 
jrpark22000 said:
No. Light has an inverse square with distance. You have a couple factors fighting you, one is resisatance. Your optics and the water column slow the light. Two is LEDs don't dim in a linear fashion, not to mention each led will dim differently than one made by a different company or in a different wavelenght. The only way to know par with an confidance is to measure.
Click to expand...

Is there also spectrum change with the dimming? (I might have heard this from you before.)
 
Paulip said:
Is there also spectrum change with the dimming? (I might have heard this from you before.)
Click to expand...

yes, but it's more extreme when comparing the LEDs at full power and low power (ex below 25%) From my initial testing with the spectrometer, the lights I've tested from 50% power to 100% power aren't seeing much spectral shift. The spectrum gets a bit narrower at 50% compared to 100%, but otherwise it's quite close. Below 25% each LED I've tested can shift a fair amount depending on the led wavelenght or by manuf.
 
jrpark22000 said:
yes, but it's more extreme when comparing the LEDs at full power and low power (ex below 25%) From my initial testing with the spectrometer, the lights I've tested from 50% power to 100% power aren't seeing much spectral shift. The spectrum gets a bit narrower at 50% compared to 100%, but otherwise it's quite close. Below 25% each LED I've tested can shift a fair amount depending on the led wavelenght or by manuf.
Click to expand...

Exactly my concern, I bought an overpowered light fixture and need to run at a very low % of max output. Thanks.
 
who has the par meter now? figured why ship if it's local right now. I've got some 90 watt pucks from groupbuyleds and dying to know what par I'm getting!
 
Meter is checked back in and is in the same condition as post #7.

PMing next in line [MENTION=3678]goatous[/MENTION]
 
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