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Discussion starter · #41 ·
There are far more inappropriate LED installations than there are justifiable ones. New technology and new gadgets seem to get attention in that way. Being a lighting designer first, I can be the LED's strongest opponent.

That being 'said', there are a few factors that should follow. There are several luminaire types that can benefit with LEDs and really save up to 50% in energy consumption today, even before LED efficacy is raised any more.

When the IES photometric file shows a bulb fixture to be 65% efficient, that is a prime application for LEDs. A properly designed LED fixture can usually get 90% of its light out of the fixture and onto the target.

We have replaced a few 175W MH post-top globe fixtures with 80W LED retrofits that actually had higher foot candle readings than the original light source.

But a word of caution - energy savings alone doesn't make the ROI justifiable. The reduced maintenance is essential to make the day with LEDs. Use an ROI calculator before going down the LED path!
LEDs do indeed have advantage for highly directional lights. For example, in the consumer product range, many manufacturers offer R-xx shaped LED screw-in accempt lamps. The focused, narrow beam produces theatre spotlight like beam good for decorative use, but for disperse and indirect lighting, LEDs don't have any inherent advantage.

There are fluorescent fixtures with 80+ % efficiency. Not all of it is directed straight down, but allowed to scatter and spill out the top, t hen bounce off the ceiling so you'll have semi-indirect lighting that's desirable for indoor lighting.

When you said 80W LED replaced 175W MH and foot candle readings were higher, where were you making the measurements? How old was the metal halide fixture and do you suppose the cutting edge metal halide fixture using a lower wattage lamp and a compact ceramic MH(that allows better control using optics) and advanced optics to have better result than before or are you going to credit LEDs for improvement?

Top tier LEDs maintain output better than the average MH, HPS maintains lumens better than LEDs. LEDs maintain 70% in 50,000 hours, while HPS maintains 80-90% before reaching end-of-life at 30,000 hours and more or less ambient independent. After allowing for LEDs higher depreciation and adverse impact from high ambient, a lower output HPS can be used to maintain the 70% of what LEDs would put up new.

output checks on new install, of course, compares non-depreciated LEDs to HPS or MH that's been depreciated.
 
Re: My impression of LED street light from field visit

When you said 80W LED replaced 175W MH and foot candle readings were higher, where were you making the measurements? How old was the metal halide fixture and do you suppose the cutting edge metal halide fixture using a lower wattage lamp and a compact ceramic MH(that allows better control using optics) and advanced optics to have better result than before or are you going to credit LEDs for improvement?

Top tier LEDs maintain output better than the average MH, HPS maintains lumens better than LEDs. LEDs maintain 70% in 50,000 hours, while HPS maintains 80-90% before reaching end-of-life at 30,000 hours and more or less ambient independent. After allowing for LEDs higher depreciation and adverse impact from high ambient, a lower output HPS can be used to maintain the 70% of what LEDs would put up new.
The measurements were on the ground at same positions for both lights.
The MH was aged, not sure how old, but by your figures (above) it probably had at least 85% original lumens.

Lots could be redesigned to better utilize the bulb for better luminaire efficacy. However, the bulb size and associated optics size would make that a strange looking fixture. In that regard, the LEDs make optical design way more practical.

The reduced maintenance aspect is where the LED pays back, and typically in the best of circumstances, HID is relamped twice during the LED life. When scheduled maintenance involves a bucket truck and two men, the energy savings is gravy.

I am working with a college that will retrofit 400 globes with our LED product, for less than half the cost the OEM wants for their LED package. They are doing it purely for maintenance savings because staff has other things to do. The retrofit is a pretty sweet job for a contractor.
 
Discussion starter · #43 · (Edited)
The measurements were on the ground at same positions for both lights.
The MH was aged, not sure how old, but by your figures (above) it probably had at least 85% original lumens.
My figures were for HPS. Standard MH depreciate much worse. They lose as much as 40%.


Lots could be redesigned to better utilize the bulb for better luminaire efficacy. However, the bulb size and associated optics size would make that a strange looking fixture.
Have you seen the newer ceramic tube metal halide system? The arc is in a small sphere with a 1/2" arc length and the bulb itself is substantially smaller than the common HPS or MH you see today. These are rated 20-30K hours, and 80% @ 20,000

http://www.lighting.philips.com/us_en/browseliterature/download/elite_design_guidev7.pdf

GE and/or Sylvania may have something similar. The initial system efficacy (line to lamp) is over 100Lm/W), which includes ballast loss.

In that regard, the LEDs make optical design way more practical.
How so? the 12mm/0.5" spherical near point source is much easier to control with optics than multiple sources scattered about.

The reduced maintenance aspect is where the LED pays back, and typically in the best of circumstances, HID is relamped twice during the LED life. When scheduled maintenance involves a bucket truck and two men, the energy savings is gravy.
Majority of lighting cost is energy and maintenance is not a huge portion.

Hardware is a very small portion too, however if LED system is outrageously expensive, it wouldn't be so.

I am working with a college that will retrofit 400 globes with our LED product, for less than half the cost the OEM wants for their LED package. They are doing it purely for maintenance savings because staff has other things to do. The retrofit is a pretty sweet job for a contractor.
If they have a good group re-lamping program and a get a competitive bid on such maintenance, it shouldn't be too bad.

Do your LED products have a system efficacy starting at 100+ lm/W) maintaining 80 lm/W @ 20,000 hrs across all operating temperatures and competitive in cost?

They have 3,000K and 4,200K, so I suppose 3,000K is more appropriate where it was traditionally HPS and 4,200K where it was traditionally MH. The CRI rating on them is >90

While the relamp interval for ceramic MH maybe twice that of replacement interval of LED, what's the cost to REPLACE the LED labor + hardware? Is it less than labor+ceramic lamps to replace them twice?

I'm just looking at your offering:
http://www.streetlightingfla.com/LED-Globe.htm

4690 lumen @ 70W, and that it requires an external driver. So, 67lm/W doesn't even factor in ballast loss. You're looking at about 60 lm/W after driver loss. You're looking around 42lm/W at 50,000 hours after 30% depreciation.

You can get 4300lm from a 57W amalgam PL-T CFL for applications where 210W MH is too big. The Amalgam CFLs are rated for near full output from 15F to 130F. It'll be 67 to 70 lm/W after ballast loss and lamp life is around 20,000 hours @ 12hrs /day. Lumen maintenance is in 85% range. Trade off is that, lamps need to be replaced every 15,000 hours or so, but it will never dip down to 70% output, so the power can be lower.

4300 * 0.85 = 3655 57W/90% driver = 63W
4690 * 0.7 = 3300 70W/90% driver = 77.7W

With 400 fixtures, the CFL option provides same maintained output and uses 2500kWh/year less, which translates to $300/yr less in energy for CFL option at 12c/kWh.

It appears the CFL solution provides similar maintained lumen at 20% less power, albeit more relamp cycle where most of cost is labor. As for LED, when it comes for replacement, I'm expecting hardware cost is substantial, so I'm not sure what is ultimately cheaper when you consider 12 year aggregate maintenance cost inclusive of LED module replacement@ 12 year mark.

The light distribution is 360deg cylindrical in this application, so the CFL sticking base down and your LED thing should be equally suitable. The CFL system offers higher efficacy.

CFLs require ballasts, your LEDs require drivers, so we can assume that these components can fail in either setup
 
Re: My impression of LED street light from field visit

My figures were for HPS. Standard MH depreciate much worse. They lose as much as 40%.

Have you seen the newer ceramic tube metal halide system? The arc is in a small sphere with a 1/2" arc length and the bulb itself is substantially smaller than the common HPS or MH you see today. These are rated 20-30K hours, and 80% @ 20,000
The initial system efficacy (line to lamp) is over 100Lm/W), which includes ballast loss.

How so? the 12mm/0.5" spherical near point source is much easier to control with optics than multiple sources scattered about.

Majority of lighting cost is energy and maintenance is not a huge portion.

Hardware is a very small portion too, however if LED system is outrageously expensive, it wouldn't be so.

If they have a good group re-lamping program and a get a competitive bid on such maintenance, it shouldn't be too bad.

Do your LED products have a system efficacy starting at 100+ lm/W) maintaining 80 lm/W @ 20,000 hrs across all operating temperatures and competitive in cost?

They have 3,000K and 4,200K, so I suppose 3,000K is more appropriate where it was traditionally HPS and 4,200K where it was traditionally MH. The CRI rating on them is >90

While the relamp interval for ceramic MH maybe twice that of replacement interval of LED, what's the cost to REPLACE the LED labor + hardware? Is it less than labor+ceramic lamps to replace them twice?
I don't know how much the MH depreciated, but the customer is quite pleased with the comparable lighting for the majority of the life with no relamping required for so many years.

I will pass the CMH info along to my HID counterpart at factory. Thanks.

LEDs are hemispherical emitters, so optical control can be quite specific and very accurate. With the LED, clever reflector design can utilize its Lambertian output very effectively, but that is getting off topic.

Energy for lighting is a large expense, but here we are comparing savings which is a delta, and the LEDs can practically save only about 50% if giving comparable light. But as I said before, sometimes their output isn't suitable.

LEDs can be selected for CRI, and 90 easily accomplished, but seems it's overkill for outdoor lighting. This is one of those options that can push cost of either technology over the mark. Even 70 or 80 is better than today's norm.

The maintenance issue of equipment and time remains the real benefit, if the LED can light the job. Replacement labor figures for our globe retrofit are equivalent to changing a light bulb. Payback is less than 3 years for a 6-12 year product, after which, you replace the whole kit (for a lower price at that time).
 
Discussion starter · #45 · (Edited)
For that acorn street light application, you just basically need a lamp that radiates in 360 degrees on horizontal axis.

Also, shorter arc HID is a single point high intensity source. It is a lot easier to make optics to distribute light from such a source than a whole bunch of small emitters.

57W PL-T shouldn't be more than $10 wholesale and ballasts are readily available. For the acorn application, CFL provides superior efficacy, better color consistency from lamp to lamp, and much lower cost upfront. I don't think ballast + lamp + socket would cost much more than $75 or so in a kit even if you spec shall be "OSI/GE/Philips only for ballast and lamp". Of course, depending on volume. CFL setup I presented above uses 20% less energy while providing the same maintained output as your LED.

It's costly to bring out equipment for service many times. If it's a college campus, you setup for group relamping (replace every lamp, or in sections) on say, Sunday morning.

Now, how much does your LED thing cost, module alone?

Just like CFLs, LEDs will suffer from ballast failure too.

CFLs only lose 15% during lifetime. For the LED system, you need to design the system so that 70% of initial output is considered adequate (which you can test by using a dimming driver to dim to 70% using new components) Consequently, despite more frequent maintenance, you can specify lower wattage lamp for CFL.

Add that triple tube lamp and associated ballasts are industry standard, so you are not tied to one supplier.
 
Re: My impression of LED street light from field visit

For that acorn street light application, you just basically need a lamp that radiates in 360 degrees on horizontal axis.

Also, shorter arc HID is a single point high intensity source. It is a lot easier to make optics to distribute light from such a source than a whole bunch of small emitters.

57W PL-T shouldn't be more than $10 wholesale and ballasts are readily available. For the acorn application, CFL provides superior efficacy, better color consistency from lamp to lamp, and much lower cost upfront. I don't think ballast + lamp + socket would cost much more than $75 or so in a kit even if you spec shall be "OSI/GE/Philips only for ballast and lamp". Of course, depending on volume. CFL setup I presented above uses 20% less energy while providing the same maintained output as your LED.

It's costly to bring out equipment for service many times. If it's a college campus, you setup for group relamping (replace every lamp, or in sections) on say, Sunday morning.

Now, how much does your LED thing cost, module alone?

Just like CFLs, LEDs will suffer from ballast failure too.

CFLs only lose 15% during lifetime. For the LED system, you need to design the system so that 70% of initial output is considered adequate (which you can test by using a dimming driver to dim to 70% using new components) Consequently, despite more frequent maintenance, you can specify lower wattage lamp for CFL.

Add that triple tube lamp and associated ballasts are industry standard, so you are not tied to one supplier.
Even globe lights require cutoff these days, and need various IES distributions (2, 3. 5. etc.). We handle these requirements.

The payback period is as close as I will get to the price. It's not retail, it's in our distribution network and bids in process. I expect you understand.

The drivers we use are rated for 100,000 hours, and frankly, in a lot of years I don't remember one failing.

It sounds like you could approach the colleges and other Facility Management operations and sell them new lighting with a maintenance contract.
 
Discussion starter · #47 · (Edited)
Energy for lighting is a large expense, but here we are comparing savings which is a delta, and the LEDs can practically save only about 50% if giving comparable light. But as I said before, sometimes their output isn't suitable.
How is the output not suitable if it is giving comparable light? It isn't suitable because it isn't putting out comparable output.

If reduced output is acceptable, there's no reason to plunk the expense of LED. You can simply reduce the number of lamps or reduce wattage using the existing technology, or as I said, using advanced CFLs and HIDs, which are cheaper than LED.

LEDs performance is disappointing for the cost. That LED module you offer is no better than screw in CFL you buy at Home Depot after you add in the driver loss, at much much much higher cost.

Even though they're generally less efficacious than best available discharge technologies, there's a false impression that LEDs are more green because they contain no mercury. Some places use LEDs, as someone else already mentioned, perception of being treehugger friendly institution/business, just like cities using hybrid for meter readers, parking enforcement, etc even if the ROI is unacceptably weak.
 
I put a few of those LED's that replace 48" T8's. Some salesman talked the city into buying a few to try out first. They run on line voltage of 277 volts. Basically you remove the ballast (or just bypass it), and wire the bi pin sockets direct.

They have already failed (all of them) in 2 months. At $90 a tube, that is not acceptable. I didn't like the light quality either, but my opinion on the light quality does not matter. The lights failing so quickly does matter.

I also posted a while back about LED street light problems in Long Beach, Ca. I won't re post it again, search this forum you can find it. Posted around April or May.
 
I put a few of those LED's that replace 48" T8's. Some salesman talked the city into buying a few to try out first. They run on line voltage of 277 volts. Basically you remove the ballast (or just bypass it), and wire the bi pin sockets direct.

They have already failed (all of them) in 2 months. At $90 a tube, that is not acceptable. I didn't like the light quality either, but my opinion on the light quality does not matter. The lights failing so quickly does matter.

I also posted a while back about LED street light problems in Long Beach, Ca. I won't re post it again, search this forum you can find it. Posted around April or May.
Department of Energy reviewed LED T8's twice in the last 2 years and concluded they cannot come close to replacing real fluorescent T8's. I have their report here somewhere, but any of you that have tried them already know this.

It's a pretty simple Physics problem. In a round about way, DOE says that fluorescent replacements require the LEDs to be packaged with an integrated heat exchanger as the whole package; the T8 half-round aluminum cannot adequately handle the heat.

I looked for your post on LED streetlights but didn't find it yet. Will keep looking. Thanks in advance for that.
 
Re: My impression of LED street light from field visit

If reduced output is acceptable, there's no reason to plunk the expense of LED. You can simply reduce the number of lamps or reduce wattage using the existing technology, or as I said, using advanced CFLs and HIDs, which are cheaper than LED.

Even though they're generally less efficacious than best available discharge technologies, there's a false impression that LEDs are more green because they contain no mercury. Some places use LEDs, as someone else already mentioned, perception of being treehugger friendly institution/business, just like cities using hybrid for meter readers, parking enforcement, etc even if the ROI is unacceptably weak.
That is exactly my point - if less light is acceptable, use smaller bulbs. But LEDs should give the same light for that money.

There are two modes used these days to justify LEDs: 1) the point you cited, they are overwhelmed with LED hype, green, RoHS, all that stuff, and will pay almost any price just to say they have LED lighting; 2) long life, theoretically zero maintenance for a decade+.

#1 is nonsense and we can't make that business model work.
#2 has demonstrated value; it does sell product to the owner, to the bean counter and also even to the environmentalist.
 
Department of Energy reviewed LED T8's twice in the last 2 years and concluded they cannot come close to replacing real fluorescent T8's. I have their report here somewhere, but any of you that have tried them already know this.

It's a pretty simple Physics problem. In a round about way, DOE says that fluorescent replacements require the LEDs to be packaged with an integrated heat exchanger as the whole package; the T8 half-round aluminum cannot adequately handle the heat.

I looked for your post on LED streetlights but didn't find it yet. Will keep looking. Thanks in advance for that.
I'm sorry my post was in response to a thread called "Induction lighting to replace HID" started by someone else. It maybe hard to find without that information.
 
Discussion starter · #52 · (Edited)
That is exactly my point - if less light is acceptable, use smaller bulbs. But LEDs should give the same light for that money.

There are two modes used these days to justify LEDs: 1) the point you cited, they are overwhelmed with LED hype, green, RoHS, all that stuff, and will pay almost any price just to say they have LED lighting; 2) long life, theoretically zero maintenance for a decade+.

#1 is nonsense and we can't make that business model work.
#2 has demonstrated value; it does sell product to the owner, to the bean counter and also even to the environmentalist.
#2, "long life" is not true. LEDs tend to not "burn out" or stop working, but they continue to depreciate in performance, at a faster rate than top end discharge lighting products. 30% depreciation is abysmal. T8 fluorescent loses 6-8% over 40,000 hours. LEDs lose 30% over 50,000. Remaining lit doesn't mean they're still fit for use. I don't see why LED drivers are any more/less reliable than fluorescent ballasts, because they're practically the same thing. Switching power supply. Maintenance free isn't same as energy free, and higher efficacy product that can produce the same maintained light for less energy, but requires some maintenance can be cheaper. Just because it sells doesn't mean its a good product btw ;)
 
Re: My impression of LED street light from field visit

#2, "long life" is not true. LEDs tend to not "burn out" or stop working, but they continue to depreciate in performance, at a faster rate than top end discharge lighting products. 30% depreciation is abysmal. T8 fluorescent loses 6-8% over 40,000 hours. LEDs lose 30% over 50,000. Remaining lit doesn't mean they're still fit for use. I don't see why LED drivers are any more/less reliable than fluorescent ballasts, because they're practically the same thing. Switching power supply. Maintenance free isn't same as energy free, and higher efficacy product that can produce the same maintained light for less energy, but requires some maintenance can be cheaper. Just because it sells doesn't mean its a good product btw ;)
I am not clear what you are trying to say in that post.

Despite my agreeing with many of these matters, the facts of LED long life seem to get all twisted up. Some of the figures you've stated aren't correct, and seem to change as required for some anti-LED position.
 
To leave or remove street lights is a whole different topic...

This topic is dedicated to point out that, LEDs can not perform comparably to existing discharge lamps or have high enough efficacy gain to offset its outrageous initial cost.
Although this conversation has continued - and in a very good and informative direction. I agree LED's are not ready yet for most applications, but if the argument is cost - 'removal' is and should be a consideration.

Sure I know we're all in the biz of selling wire and things wire goes to. But from the 'environmental' and 'consumer' point of view - sticking with HID sources of illumination is an option that makes little sense. If the point of the comparison was reducing costs and improving efficiency. It's a desperate grab to say 'we'll get better' when it 'can't really'. All of the LED manufacturers out there are driving technology just to secure patents that will eventually make them money - money that people are WILLING to spend to step forward into the future.

Unless HID technology really makes some huge steps forward - it won't be even be considered in the market (Because it is what you're trying to replace) - where compromises in light quality mean nothing when compared with the 'Greener' it is counts for more points - regardless of cost.

Some day soon - you may be showing up to compare the HID's, LED's and HO floro's with the light of the moon.... :thumbsup: Or another alternative - who knows? ~ night vision technology...

Who really gets to see this anymore:

http://vimeo.com/14352658

Hit the "full Screen" button
and
Turn up the volume if you have good speakers..




.
Very very Koyaanisqatsi - big art film of the 80's? But in one way kind of reverse.... Big sky... then Baja 500 cars.... Beautiful sky though...
 
Discussion starter · #56 · (Edited)
I am not clear what you are trying to say in that post.

Despite my agreeing with many of these matters, the facts of LED long life seem to get all twisted up. Some of the figures you've stated aren't correct, and seem to change as required for some anti-LED position.
If the LED used for your "power on" indicator on your TV consumes 15mW and 15 years later, it stays on, but decayed to 1/3 of original luminous output while continuing to consume 15mW, it is irrelevant as long as it doesn't "burn out".

For LEDs used in lighting, it is relevant. Even if it's not "burned" out, the output has dropped enough while consuming the same energy that efficacy becomes unacceptably low.

So, if 1.0 unit of light is required and you're propsing LEDs with 50,000 hour maintenance interval and 30% depreciation, you'll have to calculate design with 43% more output than needed to ensure proper output is maintained until maintenance interval is reached. 1.0/0.7 =1.43. You could have the system running at full power, or use a light-output feedback dimming control, so that its powered on at partial output in the beginning and ramp up to compensate for chip decay... Think more $$$$ for control circuitry. Not only would you need a dimming driver, you'll need a sensor based feedback system.


If it only decays to 85%, how much does it have to be overlit by at the beginning? By using CFLs or ceramic metal halides that only depreciate to 85% of original output by the time they reach their useful life/burn out, the initial output would only need to be 1.0/0.85 = 1.17, or only 17% over spec'ing of initial lumens is required. On top of this, top end discharge technology actually have higher SYSTEM efficacy, so the actual electrical energy needed to provide the required output is less. If you were to design group re-lamping for LEDs when chips have degraded to 85% output, you'll need them replaced before 50,000 hours.

Read up on LED IESNA LED life guideline. Unlike conventional lamps, they don't "burn out" so, they're rated to hours at which they reach 70% or 50% output, which is discussed in LM-79 and LM-80. Traditional metal halide lamps do decay to these points during their lifetime, but HPS, CFL, fluorescent and high-end ceramic tube MHs do not.

LEDs do decay when they're used at economically practical power density and temperatures seen in real world installs.

Even your own website fully admits to "50,000 hours to 70%"
It's true a good percentage of CFLs and HIDs actually "burn out" before 50,000 hours, but, if the percent of initial output maintained was around 85% at time of failure, and you raise the expectations on required lumen maintenance to 85%, do you find that LEDs to still hold the 50,000 hour claim?

Am i wrong here?

Here is the induction thread referenced:

http://www.electriciantalk.com/f8/induction-lighting-replace-hid-8276/

Also curious to find out how the maintenance and failure rate has been on the LED install done in the 10 story building mentioned.
As for induction, if you read the Sylvania technical paper on it, you'll find that they're comparable to CFLs when it comes to phosphor degradation. They don't have electrodes to wear out and burn out, but the phosphors do degrade and depreciate.
 
Discussion starter · #57 ·
I put a few of those LED's that replace 48" T8's. Some salesman talked the city into buying a few to try out first. They run on line voltage of 277 volts. Basically you remove the ballast (or just bypass it), and wire the bi pin sockets direct.

They have already failed (all of them) in 2 months. At $90 a tube, that is not acceptable. I didn't like the light quality either, but my opinion on the light quality does not matter. The lights failing so quickly does matter.

I also posted a while back about LED street light problems in Long Beach, Ca. I won't re post it again, search this forum you can find it. Posted around April or May.
An interesting test before committing to a project would be to order a dozen or so, send them to a testing lab and record the data. Use them in the restroom or something. Send the same lamps back to the same testing lab and see how bad they've depreciated in two years are so. Some LEDs depreciate BADLY
 
Led

I prefer the glow of LED over that of LPS street lights, but think the infrastructure doesn't need to change till it's broke... we invested in one system for the long haul, now lets use it till we've got our monies worth (not negating other factors).
 
Discussion starter · #59 ·
I prefer the glow of LED over that of LPS street lights, but think the infrastructure doesn't need to change till it's broke... we invested in one system for the long haul, now lets use it till we've got our monies worth (not negating other factors).
LPS is perhaps the highest real life efficacy available with efficacy hovering around 180Lm/W and they have exceptional lumen maintenance with close to zero depreciation over useful life of 18,000 hours or so. I have only seen it a few times and it is very rare. It is a monochromatic light and everything appears in shades of orange with zero color rendition ability.

The orange lights on streets are HPS, which still looks orange, but have some color rendering ability, good lumen maintenance and high efficacy.
 
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Discussion starter · #60 · (Edited)
All LED gas station lighting

Here is a brand new ARCO am/pm gas station all pimped out in LED lights, yet too cheap to accept credit cards.

Is it bright enough? Let me tell you that photos don't tell you jack, because you can play with exposure settings to make the "LED technology" look as good as you want, or tone down the competing technology as much as you want. Even using automatic exposure, the light meter will average differently.

We can create this before and after like effect with just a bit of difference.

ISO 50 F/5.2 at 0.6 seconds if we were to call this "before"


Same settings, but exposed for a whole second. It now suddenly looks "brighter" If the photo was composed in such a way to conceal the neon, the MH in background and the lighting inside the store, this would make a great deceptive "after" or "our brand" vs "their brand" .


ISO 50 F/3.0 0.2 seconds
You can make it "look just as bright" as "MH" technology playing photographic magic.


Visually, and subjectively, I'd say the place was lit up adequately for the intended purpose. I don't know the actual power consumption of the LED setup compared to the cutting edge MH like Philips CMH or F54T5/HO fluorescent system though.

Perhaps the Energy Trust or something alike paid a subsidy for this project whether or not there's real merit.
 
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