![]() |
|
#1
|
|||||
|
|||||
![]() The only reason I commented on the comparison to MH is because it was already being done in this thread with statements like:
Quote:
Quote:
The PAR38 light in the review used 40 degree optics and through the air lit a 7" circle at 200 µmol/sec/m2 at 18" THROUGH THE AIR (repeated for emphasis). The narrower optics would be expected to provide more "punch" than 60 or 80 degree optics. Therefore the usable light for moderately light demanding corals is about a 7" circle fewer than 18" away from the light THROUGH THE AIR (corals would probably have to be even closer due to PAR loss if measured through water). If we assume PAR is lost through the water and need to bring the PAR values up while still using the single light the light would need to moved closer to the tank making the irradiated area even smaller (based on the bell shaped dispersion of light probably closer to a 5" diameter). I understand and appreciate that the 27W O.C ICE CooL.E.D utilizes more LEDs with wider optics than the reviewed 21W PAR38 but until real data are compiled an assumption about superiority is just that - an assumption. PAR values through water depicting spread and intensity at varying depths (similar to that done in the above noted review) would certainly help legitimize this light if indeed it does provide substantially greater PAR with wider coverage than the PAR38 So again, I think the lights are useful for spot lighting small areas probably no larger than a single "large" colony of 7" in diameter with usable PAR. And again, the comparison to MH was already being made and I was simply pointing out that actual data don't support the claims being made. This form factor for LEDs is good for spotlighting small areas. An array of LEDs is certainly a better bet for more typical display sizes. Unfortunately there has been a lot of unsubstantiated hype about LEDs and now that real data are starting to become available broad sweeping claims with comparison to MH need to be tempered. I've been excited to use LEDs and had wanted to buy one of these spotlights about a year ago but decided not to be a guinea pig as an early adopter and wait until real data became available. As it stands now it looks like the best bet for me is something like the AI modules as I don't have the desire to go the DIY route.
__________________
SPS Dedicated 24x24x20 Trimless Tank | 20 g Sump | Bubbble King Mini 160 Protein Skimmer w/ Avast Swabbie | NP Biopellets in TLF Phosban Reactor | ATI Sunpower 6 x 24W T5HO Fixture | EcoTech Vortech MP20 | Modified Tunze Nanostream 6025 | Eheim 1260 Return Pump | GHL Profilux Standalone Doser dosing B-Ionic | Steel Frame Epoxy Coated Stand with Maple Panels embedded with Neodymium Magnets "Mens sana in corpore sano" Last edited by Canadian; 04-04-2010 at 03:11 PM. |
#2
|
|||||
|
|||||
![]() Andrew:
You probably already know about the Maxspect, just another option if you want to give LEDs a shot and don't want to break the bank. I don't know, people using them seem to be getting pretty good results. I'm sure there will be many more companies coming out with fixtures over the next couple of years, I'm anxious to try them myself, just holding off for a while. http://reefcentral.com/forums/showthread.php?t=1817995 |
#3
|
|||||
|
|||||
![]() A bunch of good points from everybody. As I see it if you want high PAR in a fairly deep tank then 400W MH is probably the best option. for tanks up to 24" deep I feel that LEDs can be set up to perform as well or better than many MH setups. The performance of MH is dependent on the bulbs and reflectors used and some are better than others. Same thing with LEDs. Depending on the LEDs used, the spacing of the emitters and the optics used you get varying performance. The thing about LEDs with good optics is that it looks like the penetration is actually better than MH because the lenses focus the light better than a reflector reflecting the light into the tank. What that means is that the drop off in PAR vs. depth can be less in LEDs than MH with the use of optics.
Of course, the real performance advantage of LEDS is in lower energy consumption and not adding heat to the tank. I am fairly confident my array will perform as well a a 2 x 250W MH setup would while using only 240W of LEDs and adding less heat to the tank then MH would or even my current 8 bulb T5HO set up which uses 432W of T5. As for the Maxspect, they look okay but I'm not sold on the use of a few super high wattage LEDs rather than an array of 3W emitters with optics. They create some big hotspots under those LEDs while also being far less efficient in output per watt then the smaller LEDs. I would like to see some real independent PAR numbers etc. on them. Anybody in the Lower Mainland have one for testing? |
#4
|
|||||
|
|||||
![]() The only reason a comparison was given is because people like to reference existing technology to new ones currently coming out, it gives them a benchmark to see where it stands compared to what we know. However like mentioned in earlier posts 1 LED spotlight would never be able to replace a 250W MH in terms of coverage and still get the proper PAR value. Now with that said, i have to agree with you that the LEDs in the form of spotlights are not the best forum to light bigger tanks in, but anything up to 60-70 gallon range is still doable as long as the depth of the tank doesnt exceed 24". Evil66 himself uses i believe 4~5 bulbs over his 40g tank and he said hes been getting good results from them.
What makes me conclude that the PAR38 bulbs provide 15W of lighting is the fact that they are 3W LEDs x 5, the driver provides 700mA which takes roughly another 6W bringing the total up to 21W. (evil66 pointed this out as well in his own thread about the PAR38 spotlights) So from the very beginning there has always been 21W bulbs and never any 15W PAR38s. So if we were to test the wattage utilized by the 27W version of the O.C ICE CooL.E.D we would most likely see it pulling in the 33-35W range as it also utilizes a PAR38 driver. Great points you guys are bring out! keep this discussion rolling.
__________________
Eugene |
#5
|
|||||
|
|||||
![]() +1 on Eugene's analysis of the Nano Customs Par38 bulbs. It's a bit of clever marketing on the part of Nano Customs to quote total energy consumption rather then the actual wattage of the LEDs. Any light system will have energy losses so a 250W MH looses some at the ballast and is drawing more than 250W of electricity to drive the bulb at 250W. They have 15W of LED lighting in their bulb and use 40 degree optics to get higher PAR and penetration but in a smaller footprint. The 60 degree optics in the OC lights give a bit wider coverage but a bit lower penetration and PAR.
So for LED output count the number of emitters and multiply by the wattage they're driven at. To further complicate things some light fixtures drive 3W bulbs at 2W etc. so you aren't getting the full 3 watts of power. The whole LED thing is pretty complicated right now with many manufacturers trying different things in terms of how they drive LEDs and what LEDs are used and what optics if any. There is some hype and some BS out there but also some very good products. For a top of the line it's probably the AI units right now for larger arrays as they use the best Cree emitters with optics and put out lots of PAR. The PAR38 spots are also excellent for smaller tanks or spotlighting. You can also use a larger number of them for the bigger tanks and that will work too but you probably need at least one spotlight for each square foot or so of tank. It's a complicated right now as there are many options to work with and it is difficult to make direct comparisons with existing technologies like MH because of the wide variability in LED implementation. |
#6
|
|||||
|
|||||
![]() update! A little bit behind my weekly updates
![]() ![]()
__________________
Eugene |
#7
|
|||||
|
|||||
![]() Quote:
![]() ![]() The tank looks great, I love those trimless tanks, they're so clean looking. How about some closeups? I wanna know what all you got in there! ![]()
__________________
Christy's Reef Blog My 180 Build Every electronic component is shipped with smoke stored deep inside.... only a real genius can find a way to set it free. |
#8
|
|||||
|
|||||
![]() Quote:
![]() I'll take some close ups tomorrow...that is if i remember to bring my camera with me as i tend to forget it at home most of the time i need it. Perhaps its time to make a trip down here christy and see it in person ![]()
__________________
Eugene |
#9
|
|||||
|
|||||
![]() Quote:
![]()
__________________
Christy's Reef Blog My 180 Build Every electronic component is shipped with smoke stored deep inside.... only a real genius can find a way to set it free. |