LED Spectral Analysis: Cree, Rebel, larger Bridgelux, a few "chinese" LEDs

Discussion in 'LED Aquarium Lighting' started by redfishsc, Jan 29, 2012.

to remove this notice and enjoy 3reef content with less ads. 3reef membership is free.

  1. redfishsc

    redfishsc Feather Duster

    Joined:
    Aug 24, 2009
    Messages:
    210
    Hello 3Reef!

    Here is the result of the LED testing I did about a year and a half ago, along with a very good friend of mine who was, at the time, a Marine Biology student at UNC Wilmington. Joe was fortunate enough have been hired by SECORE (www.seacore.org) so he had to leave from Wilmington quite quickly, but we managed to get this data just prior.

    The Spectrometer was an OceanOptics S2000.
    S2000 Miniature Fiber Optic Spectrometer

    There are too many graphs to post them all here (28 graphs total) and about half of them are more for planted tank owners.


    Here is my photobucket album with them all. Please browse, share, link, whatever. If you sell these LEDs, you are welcome to use the graphs on the site.
    http://s919.photobucket.com/albums/ad39/re...TING/?start=all


    Here are a few of the most important ones, but please by all means look at the rest of them. Some interesting stuff was found. Most of it predictable but nice to know for sure.

    Y-Axis is not PAR but a unit of intensity that the meter assigns. We are looking for a way to convert this number into something useful, but it serves as a great comparison.

    Rebel Neutral White and 2 Royal Blues
    [​IMG]

    Rebel Neutral White, Royal Blue, Cyan
    [​IMG]

    Cree XPG Neutral White, 2 XPE Royal Blue
    [​IMG]

    XPG Neutral White, XPE Royal, XPE Blue ("cool blue")
    [​IMG]

    XPG Neutral White, XPE Royal, Rebel Cyan
    [​IMG]

    XPG Cool White and XPE Royal Blue
    [​IMG]

    XML Cool White at various drive currents
    [​IMG]




    A few others. Please note that the Bridgelux LEDs in this thread ARE ABSOLUTELY NOT the common cheap import "bridgelux" LEDs that sell for $2 each. These are real deal Bridgelux that I bought myself from Newark. They are 10-watt LEDs (they are 402 models).

    [​IMG]

    [​IMG]

    [​IMG]

    [​IMG]


    There are others on the album as well, including individual shots for the XPG cool, neutral, and warm white.... royal blue and blue, cyan rebel, XPE red and satistronics red, and various white-only combinations for planted tanks and refugia.
     
    Last edited: Jan 29, 2012
    1 person likes this.
  2. Click Here!

  3. redfishsc

    redfishsc Feather Duster

    Joined:
    Aug 24, 2009
    Messages:
    210
    By the way, these graphs are VERY encouraging. It shows that LEDs are very balanced in their spectral output--- compared to the spiked nature of T5 and halide bulbs.


    This also could explain partly the phenomenon of LEDs frying corals even at somewhat lower levels. Corals from tanks driven by halides/T5's are not accustomed to this sort of light, and are not prepared for it, even when at the same PAR level.


    I routinely buy corals from a coral farm (greenhouse, using filtered sunlight) and I have NEVER light-shocked a coral from them under LEDs, even when their coral came from 100 micromols or less and were placed in 150-200 micromols of LED light.
     
  4. exactlyobp

    exactlyobp Giant Squid

    Joined:
    Jan 24, 2011
    Messages:
    3,984
    Location:
    Cedar City UT
    Great study!!

    Its amazing how cool white and royal blue overlap each other in spite of the "looks" to human eyes. I hope people who are thinking DIYing LED will get some idea and what is "missing" in regular 1:1 (CW:RB) combo.
     
  5. redfishsc

    redfishsc Feather Duster

    Joined:
    Aug 24, 2009
    Messages:
    210
    What is missing?

    If you compare these two graphs, you'll see that (all things being equal.... current, optic angle, distance, etc) the 1:1 cw:rb combo actually gives you more of the red/orange/amber/yellow spectrum than the 1:2 nw:rb------- and it's still vastly superior to the spectral curve of any 10K-20k halide I've ever seen.

    It's not a huge difference, but the 1:1 cw:rb combo has a light spread similar to the nw:rb:rb, but peaks at a little bit more over the "50" mark than the nw:rb:rb--- and the blue peak isn't nearly so high, meaning there's definitely more white light in the cw:rb than in the nw:rb:rb

    [​IMG]

    [​IMG]



    All that said, the nw:rb:rb is my preferred combo. Over my 11g nano I have actually even warmer light than that--- 3 warms, 3 neutrals, and 12 royals. Looks wonderful.

    Here's a shot that I do admit to messing with using Picasa photo editor, because my camera just won't get the color right. On my monitor, this is nearly identical to how it looks in person, minus a tiny touch of purple. But this is very, very close.

    [​IMG]
     
  6. exactlyobp

    exactlyobp Giant Squid

    Joined:
    Jan 24, 2011
    Messages:
    3,984
    Location:
    Cedar City UT
    I meant to say there are missing spectrum like 420 and 500nm. Ive recently built an LED fixture with:
    12 cool white (cree xp)
    12 royal blue (cree xp)
    12 neutral white (cree xp)
    6 blue (cree xp)
    6 UV 420nm
    8 UV 398nm
    4 turquoise (supposed to be 495nm but looks 510ish)
    for my regular 90 gallon.
    Its been only two months, yet I started to see some ripened colors on SPS, thanks to the UVs, I believe. (I had 1:1 CW:RB over the same setup for 6 months prior to the rebuild.)

    (Here is my build thread. )
     
  7. Dingo

    Dingo Giant Squid

    Joined:
    Aug 1, 2009
    Messages:
    4,767
    Location:
    New Freedom, PA
    I also run a UV and blue actinic over my tank. My colors have only gone brighter since.
    Great data here though, I have been waiting for this for a long time!
     
  8. Click Here!

  9. redfishsc

    redfishsc Feather Duster

    Joined:
    Aug 24, 2009
    Messages:
    210
    OK, I see what you mean.


    I'm personally not sold, in the least, on the cyan/turquoise craze. I have a few of them over my freshwater tank and really don't like them all that much. They add a bit of blue/green to the water but also really compound the shadow/disco effect.

    UV's, on the other hand, look nice if you have large enough numbers of them but they certainly could only improve the situation. They aren't cheap but they are probably useful to the corals.
     
  10. dowtish

    dowtish Horrid Stonefish

    Joined:
    Jan 29, 2011
    Messages:
    2,062
    Location:
    Nashville TN
    Wow, thanks man for posting this, there are tons of folks that have been wanting to see something like this. thanks for the time and effort
     
  11. redfishsc

    redfishsc Feather Duster

    Joined:
    Aug 24, 2009
    Messages:
    210
    Glad to have done it. I did this like a year and a half ago and for whatever reason, never really posted it here.


    I wish I could just buy a radiometer like the one we used but they are like $2K.
     
  12. tharsis

    tharsis Peppermint Shrimp

    Joined:
    Apr 9, 2011
    Messages:
    413
    That is great! Good job and thanks for sharing!

    I wasn't able to find any plots for the 'chinese' leds, have you ever looked at the cheap import bridgelux from aquastyleonline?

    I would be curious how they compare to the Crees...since I own some haha. It seems more and more people are going this route because of the cost, it would be good to have a comparison IMO.