<a href=showthread.php?s=&postid=10965095#post10965095 target=_blank>Originally posted</a> by hahnmeister
I think you are misunderstanding things... So you really believe that the LB's are designed to 'grow coral' better than the LA's? Thats where you and I differ. BTW, Im the one who took the readings in Tom O's tank, and I can tell you what the light values were at any level in his tank (actually, I thought I did already in the last response) with my PAR meter. Lets just say that that if he had LB's on his tank, the problems he had would be even worse, as he would have a beaming hot-spot from top to bottom under the center of each bulb, but the sides would be left in the dark. Pretty much what I am saying is 'thank goodness' that as you move away from a LA it loses intensity... since its way too intense otherwise. You think that the Lumenarc loses intensity as you move away from it? Well, it loses density, yes. But it you will stop trying to get your info from the graph, and look at the stats in that article, you need to compare the total incidental light at various distances (provided in my last post as well), to see that the conservation of light with distance with a lumenarc is perhaps the best on the market. That 'bright patch' that a LB has isnt a bonus, its a problem, IMO. With corals, you dont want a reflector with such 'hot spots' in its output... you want the one with a more even spread.
Im tellin you... the LB is no better than the LA... its most likely worse. I was suspect of it at first just upon seeing it, but after seeing the reasouts, now I know its for sure...
"The approx. 16.5% brighter spot is directly in the center, then goes quickly down from there. At 6" away from center it's about even, then the Lumen Bright tapers quickly off. We'll be taking more spreads from different heights in the near future, but this first one is at 2' away, perfect for an 18" deep tank, with the lights 6" above the water.
Note that even the lumenarc loses approx. 50% of it's light by the time it gets out to 2'X2' spread. The Lumen Bright loses approx. 75%, which is approx. 67% less light compared to the Lumenarc which doesn't start as bright in the direct center. 33% light vs. 50% light at 2' X 2', approximately."
The greater 'spread' of a Lumenarc, if nothing else, allows it to be mounted closer to the water surface, because it can cover a wider area and still be closer to the water... to maintain its intensity as you would say. So either way you want to interpret it... also, keep in mind that these are all 'open air' tests, and that the angle of refraction of the water will bend all the light coming in to be more focused anyways... so even the LA's will be more concentrated when you add water to the system. All light entering at 45 degrees will travel at 30 degrees (from vertical) under the water, so the hot spot of the LB's will be even smaller with water, and the LA's information will be slightly different as well.
