Halide lights compared
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URL: http://www.utahreefs.com/forum/forum_posts.asp?TID=1569
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Topic: Halide lights compared
Posted By: Marcus
Subject: Halide lights compared
Date Posted: December 30 2003 at 11:02am
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Hello again. Amongst my reading I have encountered an article about Metal Halide bulbs and how they compare to each other. I have learned not to trust the manufacturer when it comes to Kelvin rating of each bulb. I am going to jot down a couple things that will hopefully help everyone ask the right questions when considering a Metal Halide bulb. The article is from a 2002 issue of Marine Fish so it does not have the new bulbs.
First of all, the light that we can see rests between 380 and 770 nanometers. Light on the lower end from about 310-400 nm is UV-A. The lower the number, the more energy the light has. Therefore, a blue light with a rating around 450 can travel deeper into the water than a red light with a rating around 675 can. This raises a question for me: Since lower nm of light travel deeper into the water, does UV-A affect our corals positively or negatively? HQI bulbs do not have a UV filter on them but Spacelights have UV filtered glass beneath the bulbs. Is it because the livestock in our tanks is closer to the surface of the water? Or is it not needed? Another interesting piece of information is that Kelvin rating for Metal Halide bulbs is a guess. The term "blackbody radiator" is used to define the color temperature of any bulbs. The blackbody radiator is a theoretical object that is a perfect radiator that absorbs all light incident upon it. In order to properly assign any bulb a color temperature, the bulb must closely resemble the blackbody radiator in spectral power distribution (spd) curve and chromaticity (color appearance). Well, Metal Halide bulbs do not have a SPD close to that of the blackbody radiator so Metal Halide bulbs are given a correlated color temp (CCT) rating. A bulb with a CCT rating implies that it matches the chromaticity but not the SPD of the blackbody radiator. I am still trying to fully grasp this concept from what I have read it appears that there are some assumed lines of color that are used to rate Metal Halide bulbs. Incandescent bulbs have a SPD closest to that of the blackbody radiator so their color temps are the most accurate. Another term used is CRI, which is the comparison of a bulb's temp to the blackbody radiator. So for example, an incandescent has a very high CRI, almost 100, so its color is pretty accurate. If another type of bulb had a CRI of 60, then its assumed color temp MAY not be completely accurate. OMG, this is going to be long. I have to take off for a bit, but I will get into the different bulbs when I get back. For legal purposes, I do recommend that everyone buy a copy of Marine Fish because its a great magazine. There, I've wrote my disclaimer. |
Replies:
Posted By: Marcus
Date Posted: December 30 2003 at 11:13am
| There are some comparisons of 400 Watt bulbs and Iwasaki's new and old bulbs. Not many people on this board have 400 Watt MH bulb and since this is an old article hopefully everyone that has Iwasaki bulbs has the new ones. So I will not be coverring those. |
Posted By: Travis
Date Posted: December 30 2003 at 1:06pm
Hey, I have 400's  . I guess I'll have to buy the magazine  .
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Posted By: Marcus
Date Posted: December 30 2003 at 1:35pm
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Travis, sorry I assumed wrong. Here it goes:
400 Watt 10000 K & 12000 K by Sunburst, Osram, and Blueline were inthis test. Even though they are rated at 10000 K and 12000 K, they have almost the exact nm. There is a huge spike right at about 450 nm for all three. Very minimal readings anywhere else on the chart. The Blueline from Champion Lighting has the highest Spectral Irradiance but Osram has the highest PPFD. All three have been reported to be very blue and have shortened live spans. Some reefers have complained about corals showing signs of low-light symptoms such as bleaching and tissue recession. The alternative is the Iwasaki 400 watt 6500 K bulb. There are multiple spikes all over the chart with 4 major ones at 425, 490, 550, and 570 (approx.) The Iwasaki bulb had a rating of 7660 CCT. I really do recommend that everyone buy this magazine. Its very hard for me to try to shrink the entire article down. Every piece of information in it is vital. Plus it does a great job of explaining the technical side of why some bulbs out-perform others. |
Posted By: Travis
Date Posted: December 30 2003 at 2:39pm
Thanks  , any idea where Ushio's come in?
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Posted By: Marcus
Date Posted: December 30 2003 at 3:07pm
| No, but I would find the tech specs on them. PPFD, CCT, and the nanometer chart. What spectrum are the Ushio's? |
Posted By: jfinch
Date Posted: December 30 2003 at 3:11pm
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Have you read these on-line articles? Effects of Narrow Bandwidth Light Sources on Coral Host and Zooxanthellae Pigments SPECTRAL ANALYSIS OF 150W DOUBLE ENDED METAL HALIDE LAMPS AND BALLASTS SPECTRAL ANALYSIS OF RECENT METAL HALIDE LAMPS AND BALLAST COMBINATIONS Lighting the Reef Aquarium - Spectrum or Intensity? ANALYZING REFLECTORS: PART I � MOGUL REFLECTORS Analyzing Reflectors: Part II - Double Ended Lamp Reflectors The Static on Static Lighting: The Properties of Light Lighting the Reef Tank: A Primer for Beginners plus a bunch on animalnetwork that I can no longer reach... ------------- Jon https://www.youtube.com/channel/UC6y_EzjI_ljbIwf2n5uNzTw" rel="nofollow - What I've been doing... |
Posted By: Travis
Date Posted: December 30 2003 at 3:43pm
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They are 10k. From the info I've seen the 400w 10k Ushio is pretty good for intensity in relation to other bulbs but I have not read anything on their spectrum quality. Maybe it's somewhere in the above links. If I can get through them all....
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Marcus wrote:Posted By: Marcus
Date Posted: December 30 2003 at 4:53pm
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Jon, no I have not had the opportunity to read those. Maybe you could give an overview like I've done.
Travis, I would get the CCT & PPFD ratings on the bulb from the manufacturer. |
Posted By: Marcus
Date Posted: December 30 2003 at 6:00pm
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250 watt Metal Halide bulbs:
5 bulbs were tested: Aqualine Busch 110.9 PPFD ALS ��� �54.98 PPFD Sunburst 37.53 PPFD Osram ���42.01 PPFD Blueline 55.58 PPFD All are rated either 10000 K or 12000 K except the Osram which is rated at 20000 K. All of these bulbs except the Aqualine Busch tested about the same along the spectrum chart. They have a large spike around 450 nm and minimal spikes anywhere else. The Aqualine Busch bulb has a much higher PPFD and has raised levels all over the spectrum including 350-400 (UV-A). This is very similar to the Iwasaki 250 6500 K bulb except more towards the 500-600nm. The Iwasaki bulb has 130 PPFD and a CCT of 7211. The CCT of the Aqualine Busch was 8084. PPFD is photosythetic photon flux density, basically the number of units of light in the 400-700nm spectrum of the bulb. PPFD is PAR measured in terms of photons. IMO, if I was going to get a mogul socket 250 watt MH, I would get an Iwasaki 6500 K for a white-yellow look and a Aqualine Busch for a blue-white look. Again, this article does not haev the new bulbs in it like the XM. There are a couple more tests, so hopefully I will get time to post them later. |
Posted By: tom-
Date Posted: December 30 2003 at 6:10pm
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I have 2 Aqualine Busch 10k bulbs for sale but I want more for them than you can buy new cheaper brands for. But I think this shows their worth it. |
Posted By: Marcus
Date Posted: December 30 2003 at 6:57pm
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175 Metal Halide 10000 K & 12000 K bulbs:
Red Sea 10000 K 71.06 PPFD ALS 12000 K 22.22 PPFD Blueline 10000 K 28.45 PPFD To make this one short the Red Sea bulb has higher rating across the spectrum chart but the Blueline has a bigger spike around 450 nm. The Red Sea bulb has a CCT of 9128 which is close to its 10000 K rating. The other two could not be computed. |
Posted By: Marcus
Date Posted: December 30 2003 at 7:08pm
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The last test was on ballasts. The three ballasts that were tested are PFO magnetic and electronic and Aromat electronic. All three were tested using a 150 HQI Aqualine Busch 150 watt bulb. Each bulb in all the tests were burned in for 100 hours prior to testing and warmed up for 20 minutes before the tests were performed. I also failed to mention that above tests were done 18" from the sensor and without a reflector and in a dark room. This test was also 18" from the sensor but with a PFO reflector and a UV shield. The PPFD ratings of this test are higher than the "naked" 400 watt PPFD so it shows what a good reflector can do.
PFO Magnetic 246 PPFD & 10147 CCT & 1.64 amps PFO Electronic 210 PPFD & 9921 CCT & 1.4 amps Aromat Electronic 209 PPFD & 10157 CCT & 1.4 amps I do not know how the wear and tear on the bulb differs from electronic to magnetic ballasts. There you have it folks. I hope this helps. I also again give all the credit to Sanjay Joshi who wrote the article for Aquarium Fish in their 2000 Anniversary issue call Marine Fish & Reef. |
Posted By: ssilcox
Date Posted: December 30 2003 at 8:08pm
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Personally I found this link interesting. It shows a side by side comparison of what visually they actually look like against each other. It also has the PAR ratings underneath. Not as technical as the others - but interesting to actually see the differences. These tests were on 250's, BTW. http://www.cnidarianreef.com/lamps.cfm - http://www.cnidarianreef.com/lamps.cfm |
Posted By: Marcus
Date Posted: December 30 2003 at 8:15pm
| Awesome link, ssilcox. I am interested to see how these XM's do in the long run. I think its amazing to see the difference in PAR and PPFD with electronic versus magnetic ballasts. |
Posted By: Travis
Date Posted: December 31 2003 at 5:36am
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Ok so I'm confused on what all of this means. According to this artical http://www.advancedaquarist.com/issues/oct2002/feature.htm - http://www.advancedaquarist.com/issues/oct2002/feature.htm posted by Jon... On a standard Ballast the 400w 10kK Ushio has 123.7 PPFD and 7650 CCT. So is this good, bad or ok?
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Posted By: Marcus
Date Posted: December 31 2003 at 2:25pm
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Good, bad, or okay is a matter of opinion.
The PPFD of 123.7 is very good compared to the ones in my magazine except the Iwasaki. The Iwasaki has a PPFD of 186 and a CCT of 7660. So the color is almost the exact same from the 6500 K Iwasaki and the 10000 K Ushio but the Iwasaki puts out more power. But the link that Jon posted doesn't say what kind of set up is being used to test the bulbs. The test in my magazine are without a reflector, in a dark room, and 18" from the sensor. |