Lighting Website Updates

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<a href=showthread.php?s=&postid=9678261#post9678261 target=_blank>Originally posted</a> by Rhodesholar
Dr Joshi

I would like to take this opportunity to thank you for the work you do and being kind enough to make it available to the reefing public at large.

thanks for the kind words.

sanjay.
 
<a href=showthread.php?s=&postid=9677686#post9677686 target=_blank>Originally posted</a> by Sanjay
I finally cleared all the backlog and updated the website with 99 more spectral plots from the last few articles I had in the reefing magazines.

The site now has 916 spectral plots.

If you find any mistakes please let me know.

thanks,

sanjay.

Have the Giesmann 250W DE labels been corrected? I'm still not sure which is the 13k vs. the 14.5K (coral vs. megachrome), as currently both are labeled 13K. Normally I would assume that the higher PAR one is the 13K...however, seeing as the 10K Giesmann has lower PAR than both :rolleyes: I don't think I can make that assumption.

TIA
 
Peter:

The Giesmann lamps do not have any Color Temp rating on the packaging. Thier lamps are labelled Marine, Coral, and Blue. The coral lamp may be the one that is being called 13K or 14.5K. It has more bluer look compared to the Marine.

sanjay.
 
<a href=showthread.php?s=&postid=9681127#post9681127 target=_blank>Originally posted</a> by Sanjay
Peter:

The Giesmann lamps do not have any Color Temp rating on the packaging. Thier lamps are labelled Marine, Coral, and Blue. The coral lamp may be the one that is being called 13K or 14.5K. It has more bluer look compared to the Marine.

sanjay.

Ah, I see. Thank you for the clarification. :)
 
I know that LED's can put out a lot of LUX as they are now using them in Tail Light Assemblies, and in a few years are hoping to use them for headlights.

Most LED's I have seen though put out a fairly narrow light band. This I would suspect may result in a lower PAR rating. Besides that Corals need several different frequencies of light, so I realy would like see an unbiased lighting spectrum on these.

I believe Sanjay does have a LED fixture. So it would be nice if he gave us some info on how the Spectrum plot looks compared to the MEtal Hides. I'd also like to see what the PAR values are.

Now as far as pricing. Yes I'll agree these are not cheap especialy when one knows that the LED's are no place near the cost of MH's. However keep in mind that this is a new product that the manufacturer probably invested a millin dollars of R and D cost, patent fees and lawyers etc. So they do have to recoop some of that cost, and have to guess how many they will sell. At $1,000,000 investment, with sales of 500 units they need to recover $2,000 per unit plus there manufacturing costs.

This is why new technology is expensive. Especialy in a market that sales are not in millions of units.

Dennis



<a href=showthread.php?s=&postid=9737180#post9737180 target=_blank>Originally posted</a> by kelvin88
Have anyone tried those LED light?, does that even work? Man they cost $$$$$
 
sanjay -

I currently run two 150W DE's on a 90. The setup was two Hamilton pendants including their ballasts and 14k lamp. I am thinking it is time to upgrade the bulbs and I was looking through your site to compare the spectral plots for other 14k lamps, but I can not find my ballast or my bulb on your list. Is there a common or similar ballast I could select to see what a Ushio 14k or Pheonix 14k bulb would perform?

Thanks,
Chris
 
LED's are a mixed bag, IMO. The actual lumens/watt ratio of the ones PFO is using is something dismal, like 20 lumens/watt (luxeon). Recently released ones are still only topping out at 60 lumens/watt (luxeon rebel). So how could they possibly compete with halides and T5s which are topping out at 85-105 lumens/watt? Reflectors/optics.

A LED is able to focus its light into the tightest, narrowest, almost laser-like focus of output. So that LED may not make much light, but what it does make, it is able to concentrate so well.

This comes at a price though. You may be able to light your 150g with one if the dimensions are 72x18x30"high, but not if its 72"x30"x18" high, because the LEDs wont cover the 30" front-to back of the tank. They are like little spotlights, so even people who try to grow corals on the back wall of their tank are having trouble, because the light drop-off is very severe when you move out from directly under the LEDs.

So the solution may be to use lenses to help spread out the light source across a wider area... well... when you widen that 15degree cone of light to 30degrees, you just cut the intensity by what... 4x, or 8x... and then LEDs have lost their advantage as well.

Companies who R&D LED technology are claiming they will hit the 150 lumen/watt range though in the next few years, and companies like Cree have already hit 130lumens/watt... so there is potential for LEDs to compete, and eventually replace halides and T5s... just not quite yet.
 
<a href=showthread.php?s=&postid=9740177#post9740177 target=_blank>Originally posted</a> by hahnmeister
LED's are a mixed bag, IMO. The actual lumens/watt ratio of the ones PFO is using is something dismal, like 20 lumens/watt (luxeon). Recently released ones are still only topping out at 60 lumens/watt (luxeon rebel). So how could they possibly compete with halides and T5s which are topping out at 85-105 lumens/watt? Reflectors/optics.

Well Yes but nopw lets look at the area of coverage. While the hides and t-5's are producing more Lums/Watt they are doing this in a 360 degree circle. So roughloy 1/4 of that is going directly into the tank while the other 75% is being reflected into the tank. So now we have an issue of the effeciency of the reflector on the T-5's and MH while with the Leds the angle is predetrmined and focusing like a little spotlight, hence 100% is going into the tank.

A
<a href=showthread.php?s=&postid=9740177#post9740177 target=_blank>Originally posted</a> by hahnmeister
LED is able to focus its light into the tightest, narrowest, almost laser-like focus of output. So that LED may not make much light, but what it does make, it is able to concentrate so well.

This comes at a price though. You may be able to light your 150g with one if the dimensions are 72x18x30"high, but not if its 72"x30"x18" high, because the LEDs wont cover the 30" front-to back of the tank. They are like little spotlights, so even people who try to grow corals on the back wall of their tank are having trouble, because the light drop-off is very severe when you move out from directly under the LEDs.

So the solution may be to use lenses to help spread out the light source across a wider area... well... when you widen that 15degree cone of light to 30degrees, you just cut the intensity by what... 4x, or 8x... and then LEDs have lost their advantage as well.

Dependent upon the MFG and type LED's come with various angles ranging from 15 to 60 degrees. However even if stick the more powerful units available today at 30 degrees we always have the option of using more LEDs to get the coverage over that 30" area.

Lens to spread out the light to me woulod be a bad option as whenever light changes medias there is some loss, through reflectance and this loss is often variable by the wave lenght which can be seen in a prism or rainbow.


<a href=showthread.php?s=&postid=9740177#post9740177 target=_blank>Originally posted</a> by hahnmeister Companies who R&D LED technology are claiming they will hit the 150 lumen/watt range though in the next few years, and companies like Cree have already hit 130lumens/watt... so there is potential for LEDs to compete, and eventually replace halides and T5s... just not quite yet. [/B]

Yes I will agree that technology is changing every day in these and many simular fields. However in the reef lighting an important thing is the distribution of light at various frequencies. Now by the virtual nature of LEDs they have narrow band widths. Therefore a mix of LED's would be required to create the balance we need in the reef.

Uner the present situation the issues are.

1. The cost of these fixtures are excessive when compared to the light they produce.
2. There is very little unbiased data out there showing if they can produce the light required to grow corals.
3. The technology is moving so fast that if you buy today what you bought will be outdated in 2 years at half the price.

I can almost look at this like the big trend for Compact Florescents about 10 years ago. Everyone jumped on the band wagon when they were high priced but new and promising. The first few years anything 6 months old was outdated with new designs being released regularly. Yet in the ling run they never did replace the MH's.

Dennis
 
Dennis,
I dont see where your post 'went'... you said 'lets take a look at coverage'... yes... but then you talk about 75% vs 100% going into the tank. I dont get it: you mention coverage, but then talk about efficiency. I suppose you are just repeating what I said, or ??? I agree, LED's get more of the light they make into the tank compared to other bulbs, but still, they lack the efficiency at 20 lumens/watt to make up for better 'reflectors', so their light is focused into the tighest beam possible. This lazer-like spotlighting of the light is a 'mixed bag'... it makes up for the weaker output, but it ends up limiting the placement of corals and the thickness of the tank you might be able to use. Using one of these units over a frag tank... say... 4' x 4' x 12"high would make no sense.

As far as using lenses to spread out the light... if you think that is a bad idea... well, you had better let phillips and cree and all the other LED mfg's know because thats how they do it.
http://www.luxeonstar.com/sub_category.php?id=327&link_str=327

The lenses that are used are made with some of the clearest materials known, so I wouldnt worry too much.

You might not have made out too well with power compacts back then, but now, dont forget, T5s are really an offshoot of that same technology (most lighting mfg's refer to PC bulbs as T5s because they are both 5/8" diameter). And T5s are competing with halides.
 
There are advantages and disadvantagtes to everything in this world.

The Spotlight effect here of the LED's can be used for or against us. If you have a tall tank then that 30 degree LED is a plus feature as it allows a greater % of the light to penetrate to the bottom of the tank than with a T-5 and especialy a MH.

Yet as you say that 4'X4'X1' tank is not the ideal for a 30 degree angle. As I look at a tank with those dimensions it would require at least 16 LED's positioned at least 12" above the tank. But then again a tank like that is chalanging to light regardless what type of light source you are using. I know because I'm ttying to find the best lighting for 30 breeder tanks !8"X36"X12".

The real worry I have with LED's though is getting a good spectrum of light. I think it would realy be great if Sanjay could plot out the frequencies that his LED fixture is putting out. Then we would get a better idea of there present usefulness.



<a href=showthread.php?s=&postid=9760821#post9760821 target=_blank>Originally posted</a> by hahnmeister
Dennis,
This lazer-like spotlighting of the light is a 'mixed bag'... it makes up for the weaker output, but it ends up limiting the placement of corals and the thickness of the tank you might be able to use. Using one of these units over a frag tank... say... 4' x 4' x 12"high would make no sense.
 
Those frequencies are in Dana Riddle's write up from August '06
http://www.advancedaquarist.com/2006/8/review2

There is a slight problem with LED's: their outputs are often very narrow. Even the white LEDs are mostly blue in output with very little else, so the Solaris as a whole lacks the red spectrum almost completely. I would like to see some 3000K LEDs added in to help the red and pink corals show better. T5s presented this 'narrow output' problem for the first time really... you can use blue, actinic, and aquablue bulbs and end up with no warmer spectrums all together... and similarly, the solution has been to add in a 3000K-6500K bulb to the mix. LEDs are even more of a problem in this manner. They are a dream if you want to be able to customize the spectrum of your tank, but a nightmare if you are trying to get as complete of a spectrum as possible. A 420nm actinic LED will put out just that... actinic. A 450nm blue LED will put out just that as well... blue, and nothing else. Leaving you with having to make a patchwork of different color LED's to get a complete spectrum.
 
You know, just sitting back and observing the discussion regarding the LED's. It seems as though you could make a LED panel with a mix of the different wavelink LED's with a digital dial to allow you to dial in the color temperature that you want.

I would also think that the LED 'rows' could be made to 'swivel' to allow for varying width tanks.

Just some random thoughts though, the technoilogy still has a long way to go.

Chris
 
The LED panel with a mix of different wavelength LEDs witha digital dial to allow you to dial in the color temps is pretty much what the PFO units are at this point. You can vary the amount of blue and white LEDs to get a whiter or bluer look. Depending on the model (there is a 13,000K and a 20,000K), the starting amout of each type of LED varies. For instance, the 20,000K also includes some 420nm LEDs if I remember correctly, and then to make up for the lagging green spectrum, there are two green LED's added to the mix to bring up the green spectrum. The yellow through red spectra though... they pretty much dont exist.
 
This is exactly what Im getting at about the LED's.

Looking up the spec on clear LED's you have a peak around 510nm which is in the blue green visual preception area. They also have all there light in the 460nm to 555nm range. This is fairly good for most individuals visual preference however there is very little photosynthesis that occurs in the green part of the color spectrum that these leds are so rich in.

You then mention the addition of the 420nm leds for blue part of the spectrum. This is simular to moon light and/or atinics. The deeper the native coral from the sea the more it requires these shorter wave lenghts.

Finally you admit that these leds are lacking in the yellow and red end of the spectrum. Yes I can see this as there are basicly no LEDs in the 555nm or longer wave lenghts that are listed. This is the red and yellow spectrum in which many shallow water corals require light in for photosynthesis.

Adding to this the factor that LED's emit light in very narow band widths we prpbably have a light spectrum put out by these hoods with high peaks at 3 or 4 specific frequencies and very little if anything emmitted other frequencies. Different photosynthesis chemicals require different specific wave lenghts so the question remains do thise lights produce light at those specific wavelenghts required for the particular coral you are trying to keep.

The other point which I hate that manufacturers do is call these light combos by K temp's which have no real sound bases. I can see natural sunlight is between 5,500K and 7,200K dependent upon time of day and location. Then moving up to 10,000K which is a more whiter light, and finally something in the 12,000K range which has a bluish tint. But when bulbs are rated at 15,000K to 20,000K this is just an artificial number, how can they make these claims.


<a href=showthread.php?s=&postid=9767331#post9767331 target=_blank>Originally posted</a> by hahnmeister
The LED panel with a mix of different wavelength LEDs witha digital dial to allow you to dial in the color temps is pretty much what the PFO units are at this point. You can vary the amount of blue and white LEDs to get a whiter or bluer look. Depending on the model (there is a 13,000K and a 20,000K), the starting amout of each type of LED varies. For instance, the 20,000K also includes some 420nm LEDs if I remember correctly, and then to make up for the lagging green spectrum, there are two green LED's added to the mix to bring up the green spectrum. The yellow through red spectra though... they pretty much dont exist.
 
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