Archive for the ‘General SSL Commentary’ Category

In a recent article published in Architectural SSL on the topic of blue light content of LEDs, I attempted to present the discussion of blue light from the perspective of those raising concerns about blue light hazards against known and practical objective knowledge on the topic. The article covered the gambit of concerns, from retinal damage concerns to melatonin levels in occupants, from both sides of the argument, as there are those who dismiss this as a non-issue out of hand. The article also forwarded two conclusive suggestions. First: The research on this specific topic, as it relates specifically to LED light sources, is a little thin. Second: For those concerned about blue light content, selecting LEDs of a lower CCT and higher CRI delivered the lowest blue light content. Whether or not this is the best choice for visual acuity was not the subject of the article, nor was it suggested as the best solution overall. There is a great deal of research supporting the concept of high CCT light for enhancing human visual performance. Much of this was completed under light sources other than LEDs, so there is no caveat included that states anywhere that blue light content of LEDs is at acceptable levels, or of no concern.

On the topic of blue light, the conversation will invariably include a mention of the fact that human kind evolved under daylight, which contains blue light, thus, there is no issue with blue light to be concerned with. That argument is nonsense of course. We also grew up under some amount of UV light as well, yet we know for a fact that this is dangerous to both our skin and eyes. When we added sunglasses to the formula to cut light to the retina, which then causes the pupil to dilate to accept more light, we soon discovered that our low grade sun shades were not filtering UV light to the same degree as visible light, which created an explosion in retina cancers and other UV related physical damages we now know to control. This is why virtually all sunglasses sold today now include specific UV filters to control damaging rays, and why we humans, evolved under the sun, wear sunblock to protect ourselves. We also live under a lot if infrared radiation, but are hardly going to be sticking our faces in the fire claiming our eyes are safe, since that IR radiation has been around since we emerged as a species. The reality is, artificial light is just that, artificial. It is not natural light, no matter how we market it. This artificial creation of light is similar to our fatty foods. The balance between what is a natural blend of fats, proteins and carbohydrates is manipulated to achieve some result that is not the same as cutting a raw slab of meat from a living animal and eating it, or simply consuming a raw unprepared vegetable. Just as we have taken what naturally nourished us in raw foods that now cause us disease, artificial light can and does contain similar liabilities. This has been the case long before LEDs, and is still with us in the solid-state age.

The IES has issued an interesting document on the topic of higher CCT light sources as a more effective approach to efficient visual performance. This is TM-24-13 ‘Adjusting the Recommended Illuminance for Visually Demanding Teasks Within IES Illuminance Categories P through Y Based on Light Source Spectrum’ (a ridiculous document name BTW), is frequently quoted by those supporting a very high CCT light source be used to enhance visual performance. However, this is not the core data point TM-24 uses to establish light source choice at all. The metric used is the S/P ratio, or Scotopic/Photopic ratio, which indicates how the spectral power of a light source supports the full range of Mesopic vision. In this document, typical sources are cited as examples, based on common lamps and light sources, from HPS to Daylight, with a relative S/P ratio for each. None of these sources were LEDs, nor was the discussion of blue light content included in the EVE (Equivalent Visual Effect) summary. There is no suggestion, positive or negative, that LEDs of any CCT support the relative EVE or S/P ratios based solely on the CCT they produce. Further, there is nothing in the document suggesting that the characteristics of LEDs will enhance or detract from the evaluations, because, simply, LED light sources were not addressed at all. The only solid conclusion one can make from this document is that a high S/P ratio is a significant factor in optimizing visual acuity. While with today’s available light sources, and using daylight as the supposed “perfect model”, it might be suggested that high CCT sources alone are the solution, this would be an overly broad, overly generalized and simplistic interpretation of the content of TM-24.

Now, that set out, let’s look into another topic I believe is being slipped by without proper scrutiny. This is the idea of modifying human biophysical responses to light by purposely introducing a light spectral power distribution to attain a desired result. Specifically I am talking about the known effect of blue light in the range of between 430 and 460nm that imparts a melatonin suppression response, with a circadian efficiency peak of 485nm+/-. It is suggested that if we purposefully manipulate and add (or allow to exist) blue light at these wavelengths, we will help people feel less drowsy and more energetic. I believe this broaches an area of ethics we as a community need to fully resolve before we accept this as a desired effect and forge ahead with high CCT light sources, believing we are reaping the benefits of better visual performance with a pep-pill bonus. We all know that adding stimulants to drinking water could reduce drowsiness in working environments. This is, of course, unethical (not to mention illegal), so we don’t do it. So, is purposefully manipulating circadian rhythms of offices and manufacturing facility employees, using light that is specifically and purposefully, in full knowledge and intent, doped to reduce melatonin levels to increase alertness? Do we know for a fact, or even beyond a reasonable doubt, that this has no long term health effects? I suggest that this is not an ethical approach to lighting, and that any attempt to purposefully amp up alertness by doping the lighting system with increased blue light without the consent and knowledge of the occupants, raises serious questions that are well beyond the realm of marketers and proponents of high CCT/high Blue light products.

This leads to the oft-cited suggestion that LEDs produce no more blue light than any other light source, thus are of no concern. The DOE has even supported this position in statements, effectively dismissing any discussion of the topic as irrelevant. What’s missing, and of critical importance, is that this generality is simply incorrect. While there are some LED sources that deliver no more blue light than other conventional sources, does this mean that the sources held up for comparison are acceptable as a baseline? How do they align with the vaunted perfect light source, daylight, and is there a way to attain what we want from light sources without the increased blue light content? In the sweeping, overly broad statements made, none of these questions are addressed, only avoided.

At various times I have suggested that high CRI LEDs of any CCT, produce less blue light as a portion of total light energy, than low CRI LEDs. This is based on LED light sources founded on the effect of phosphor conversion of either a 405nm violet, or a 456nm blue die light source. Since we are talking about blue light, as defined by melatonin suppression (430 and 460nm) the more of the core blue light of the LED that escapes, the greater the blue light presence will be. To increase CRI of an LED, more blue light needs to be down converted to the yellow-green and red wavelengths, leaving less escaping as raw blue light. Thus, the higher the CRI, and a subsequent lower blue light content as a portion of total light energy. As you will see here, this theory has its limits.

So, with this all in mind, I did a few tests of light sources to see just where we are with the blue light content issue between sources. I captured spectral data in micro-Watts per square centimeter using a Mightex CCD Spectrometer, then normalized all sources to an identical total output in watts of irradiance between 400 and 700nm, where we do most of our seeing. Withing that total output, I isolated the energy produced between 430 and 460 (>430 to <460) to see how much of the total energy produced by the source landed in the blue light zone being discussed. Here are the results:

While most spectral data comparing products shows relative distribution, its not until actual irradiance is compared that the differences between sources is revealed. In this case, all of the sources are generating the same exact total irradiance in microwatts per square centimeter, so the differences in balance between produced wavelength energies is made apparent.

While most spectral data comparing products shows relative distribution, its not until actual irradiance is compared that the differences between sources is revealed. In this case, all of the sources are generating the same exact total irradiance in microwatts per square centimeter, so the differences in balance between produced wavelength energies is made apparent. Note the red spike for the 2800K LED, which generates its high CRI rating, comes from an added red LED die in the array, not phosphor conversion.

  • 5800 K Daylight (cloudy sky)  = 98.9 CRI – 9.6% of total light energy falls between 430 and 460nm
  • 5000K Daylight (direct sun) = 99 CRI – 8.4% falls between 430 and 460nm
  • 5800K LED @ 65 CRI – 20.8% falls between 430 and 460nm
  • 5000K LED @ 90CRI – 13.1% falls between 430 and 460nm
  • 4000K LED @ 80CRI – 11.2% falls between 430 and 460nm
  • 4000K D841 T8 Fluorescent Lamp – 12.2% falls between 430 and 460nm
  • 2800K LED @92% – 6.8% falls between 430 and 460nm
  • 2500K Halogen @99.7 CRI – 2.2% falls between 430 and 460nm
While the graphic looks like a jumble, looking at it carefully reveals the ramp from lower left to upper right of halogen, the distinctive blue pump hump of the LEDs, the flatter total coverage of daylight, and the strange tri-phosphor spikes of the fluorescent source.

While the graphic looks like a jumble, looking at it carefully reveals the ramp from lower left to upper right of halogen, the distinctive blue pump hump of the LEDs, the flatter total coverage of daylight, and the strange tri-phosphor spikes of the fluorescent source. Note: In these graphics, I have reverted to relative spectral data.

The products tested ranged over and under the black body line, which is apparent when comparing them side-by-side as some yellow green, some magenta.

The products tested ranged over and under the black body line, which is apparent when comparing them side-by-side as some yellow green, some magenta. To make matters even more interesting, the poor CRI 5800K and 4000K T8 lamp came closest to sitting on the black body line, even beating daylight, while not matching its CRI (or CQS). This indicates flaws in our modeling, including and beyond CRI itself.

So much for the LED not producing more blue light myth, and the disconnect between CRI and blue light discussion. In LEDs, not only is color quality a measure of a sources visual appearance, it can be corollary to the amount of blue light one can expect to be emitted from the light sources as well – although, as I will demonstrate, this is not always true either. In other words, we must stop assuming that all CCTs generate the same amount of blue light, or that CCT alone is a meaningful single metric in determining blue light content.

Please note that all white light will deliver blue light above the described 460nm through the peak circadian efficiency peak of 485nm. This is necessary to realize any full white appearance. However, that fact does not diminish the impact of addition blue light presence below this peak, as the circadian response curve is quite broad, ranging from <380nm through 625nm.

If we use a 9% of total energy as a baseline of acceptable blue light balance in the spectral power distribution of light sources, the following conclusions can be drawn:

  • A low CRI 5800K LED produces 2.3 times the blue light as daylight
  • A 90CRI 5000K LED produces 45% more blue light than daylight, but 48% less than the lower CRI/Higher CCT LED
  • The high CRI 5000K LED generates no more blue light than an 80CRI 4000K LED or T8 fluorescent
  • The 2800K 92 CRI LED generates 25% less blue light than daylight
  • The 2500K 99CRI halogen lamp generates 75% less light than daylight

This is, by no means an endorsement of reverting to halogen light sources or call to abandon the pursuit of LEDs or high CCT light sources. What I am suggesting is that we be realistic and recognize what we are working with, and if it is possible to realize both high CCT s and high color performance, while controlling blue light content, perhaps we should. The 5000K LED at 90CRI is one example of this, we gain the higher 5000K CCT over the 4000K, with greater color accuracy, while suffering no gain in blue light. The next question is whether this is corollary to the important S/P ratio. For that, I re-measured each of the sources using the Asensetek Spectrometer to create a side-by-side comparison as it would be applied using the principles described in TM-24-13. Here are those results:

  •  5800K Daylight – S/P Ratio 2.41
  • 5800K / 65CRI LED –  S/P ratio 1.83 (does not measure within TM-24 table showing 2.0+)
  • 5000K /90CRI LED – S/P ratio 1.61 (does not measure within TM-24 table showing 1.85-2.05)
  • 4000K / 80CRI LED – S/P ratio 1.36 (does not measure within TM-24 table showing 1.6-1.8)
  • 4000K / 80 CRI T8 – S/P ratio 1.59 (at bottom of TM-24 table showing 1.6-1.8)
  • 2800K / 92CRI LED – S/P ratio 1.36 (within TM-24 table)
  • 2500K Halogen – S/P ratio 1.24 (within TM-24 table)

Not what I expected, and more than a little dissapointing. It appears that LEDs are not delivering the same S/P ratio performance as the fluorescent sources cited in the TM-24 recommendations, or the daylight and fluorescent equivalents of the same or similar CCT. Apparently more work is required here. All of the LED sources, regardless of CRI or CCT, are falling short, which indicates they will not perform better than their fluorescent counterparts. Even when the 4000K LED and T8 lamp are compared in my little test, the LED fell short. Additionally, while I personally hoped to see a connection between the CRI and the S/P ratio, this was not to be. Quite the opposite. The high CCT, low CRI 5800K LED topped the charts in regard to the S/P ratio (of the sources tested thus far anyway) while also delivering poor color performance and the greatest amount of blue light. This indicates to me there is a serious flaw in the way all of this is being evaluated that needs to be resolved. Otherwise, TM-24 S/P recommendations become antithetic to color quality, which is not an attractive prospect.

In an effort to understand this a bit more, I decided to make my own LED recipe using some remote phosphor plates and a 456nm blue array I had lying around – to see if I could mix up a very high CCT source with good CRI, yet avoid the blue light content. Here is the result:


This the CIE diagram of the two farbicated LED samples. Note how far south of the blackbody line they fall, looking a little magenta. Also, illustrates the issues with CRI, as these two did well there. CQS calculated to just 80. However, even it has no data to show how far these were off being white.

7000 and 8700 CCT LED Fabricated from Blue pump and phosphor discs

7000 and 8700 CCT LED Fabricated from Blue pump and phosphor discs

  • Fabricated 7000K LED delivered 91CRI – 22.3% falls between 430 and 460nm – S/P ratio of 2.3
  • Fabricated 8700K LED delivered 90CRI – 24.3% falls between 430 and 460nm – S/P ratio of 2.5 (spot on to the sky reference and 8000K fluorescent reference in TM-24

I was encouraged that a 7000 and 8700 CCT LED system could be made to generate 90+ CRI. Unfortunately all this did was demonstrate how poor CRI calculations are in this region, as the CQS values for these were a solid 10 points lower, while their position well below the black body line reflects their somewhat purplish presence. As a minimum, we should be given a Du’v’ value for all color ratings – but that is another topic altogether. Although, while the color looked off, it did a fair job of looking white on reflected surfaces and did render colors on my color checker nicely enough. The S/P ratio certainly looked good, nearing daylight and better than any of the other LEDs I tested before. So, at the least we can conclude that a high color rendering accuracy does not harm attaining a high S/P ratio.

The blue light evaluation produced decidedly disappointing results, delivering the highest of all sources tested so far. Obviously, a high CCT/high CRI (CQS) with high S/P ratio can be achieved while still deliver very high blue light content. So my high CRI to low blue light content argument falls apart as the CCT increases.

It also appears that there is a missing piece to this puzzle – since I can nearly duplicate daylight performance in both CCT, CRI, and S/P ratio, but deliver nearly 3 times the amount of blue light in balance compared to natural light. That means these artificial light sources have 3 times the impact on melatonin suppression than natural daylight. I do not find that a desirable result, nor should anyone else. I am not even considering or suggesting that there is any health impact other than potential sleep/wake cycle effects. While there is some research indicating blue light near the 400nm through 450nm range can cause retinal damage, there are at least as many papers indicating that retinal illuminance levels are unlikely to be high enough to be a concern. So, we’ll leave that topic for others or another time. My concern is that application of LEDs everywhere, coupled with the advantages of increased CCTs in visual performance to reduce illumination levels (to trim energy use)  means we are going to be exposing ourselves to a significant increases in spectral energies that effect our melatonin levels. Dismissing this out of hand seems reckless. As an insomniac, the prospects are not attractive at all.

The heart of the blue light issue as it relates to melatonin, is the use of the 456nm blue LED. Move to a 405nm violet LED, and the majority of the energy from the core LED falls outside the range of concern. However, being closer to UV light energy brings with it its own baggage that will need to be addressed, while most 405nm LEDs fall short of the lofty efficacy we see with 456nm products. Further, my experience with conventionally made 400nm to 405nm LEDs is they are significantly more sensitive to temperature, aggravating getting the most of them. Perhaps there is a solution in GaN on GaN architecture that resolves that issue.

Overall, if we agree that the goal is to achieve optimal visual performance, as shown in TM-24-13 – through increased CCTs to some degree, while seeking a high S/P ratio, we need to discover a way to maintain good color quality and accuracy (which begs a new standard, as the CRI is obviously not helping us here), while also managing the blue light content. It seems to me, after looking at these results, that all that blue light escaping is lost efficiency in delivering high color performance and creating even better S/P ratios for visual acuity. However, I was unable to achieve the desired result on my admittedly make-shift work bench.

So, to the origins of this discussion. While I have suggested that for those most concerned about blue light, the only real approach using LEDs available on the market today is to select lower CCTs with high CRI/CQS scores. These products use up more of the blue light to create the yellow-green and red colors necessary to achieve the higher color accuracy results. This was consistent with the test results presented here. When you get beyond 5000K, all bets are off, no matter what CRI/CQS rating the source achieves. This is especially true for spaces where high precision lighting is not the task in hand, and where relaxation before heading to bed is in order, the 2800 93CRI LED tested generates less blue, melatonin suppressing light than daylight. However, it does generate 3 times that of halogen, so there may be a case made for bedside lighting remaining conventional, or consider a light source like Soraa’s LEDs, which use 405nm LEDs as their blue pump, which is below the threshold of concern.

For high precision task lighting, the blue light issue is harder to avoid. To get the high S/P ratio means higher CCTs, often much higher than what many of us are accustomed to. While this can be done with high CRI (which does reduce blue content to some degree), it is not necessarily corollary, while most high CCT LEDs are poor in color accuracy (and very high blue content). Couple this to the fact that these applications also include use of higher illuminance levels, compounding exposure as a whole. There is also a failure in the S/P and CRI/CQS metrics when we get beyond 4000K, indicating a more careful evaluation is necessary to make solid decisions. Assuming a high CCT and high S/P ratio is the whole story is obviously inaccurate. Further, with blue light energies – as a component of total light energy – exceeding what we experience under daylight by as much as a factor of 3 (much more if you consider low CRI LEDs with much higher blue content), being cautious and conscious of the effect this might have on sleep patterns is a prudent measure. We might keep in mind that workers in construction, precision shooters, and others exposed to daylight on a daily basis have found blue light filtering glasses to be an aide to both visual acuity and comfort. Under the same CCT of LED light, there is an even greater component of blue to be considered. Whether or not this is going to be an issue, we do not yet fully understand. Whether the benefits of the higher CCT S/P ratio are negated by the high blue light content of LEDs is something else that will need to be studied and resolved.

I suggest that as time passes and LED technology develops, much of the blue light issue will fade as a combination of growth in understanding and increased conversion efficiency where that energy is used to generate improved color qualities – rather than simply allowed to escape, assuming some attention is paid to the issues raised here. In the meantime, avoiding simplistic assumptions, either for or against blue light, CCT levels, CRI/CQS accuracy, and S/P ratios and their meaning, is the first step in breaking through to greater results. Moving toward lowering blue light, raising CCT, establishing a new color accuracy metric, and establishing a metric for clearly indicating and defining the effect of spectral power on human visual and non-visual response also appear to be in order in the long term.

08285I have a fondness for the halogen lamp. From the little 20W bi-pin 12V burners to the 500W double ended monsters, the combination of light quality, simplicity, toughness, light density and versatility filled a special place in the hearts of lighting designers for decades. While there were also  larger iterations of the technology reaching 20,000W, even the most halogen crazed found them to be a bit over the top, setting them aside for special applications. In my own experience, the 20W through 75W 12V burners, 15W through 65W MR16, 35 through 50W PAR36 and 75W through 250W mini-can line voltage lamps hit the spot for a wide range of focused and unfocused lighting product designs. For my personal portable lamp works, the low voltage burners, MR16 and the PAR36 lamps were my favorites. I could create live-structures (where the fixture acted as conductor) using remote 12V power supplies, allowing sculptures to be simple to the extreme.

This simple bridge design was created using building and armature wire, a PAR36 halogen lamp, and a ball bearing counter weight.

This simple bridge design was created using building and armature wire, a PAR36 halogen lamp, and a ball bearing counter weight.

When LEDs arrived on the scene in the late 1990’s, I caught a glimmer of what was to come. By the year 2002, it was obvious that solid-state would be delivering something new, and that the properties of the source technology shared a great deal with the halogen lamp from a lighting perspective, with a huge advantage – far less heat, much tougher and resistant to impact, and very long lived. The only issue was, color quality was initially poor, consistency from LED to LED was awful, and light output per individual LED device was pathetic. This required designs utilize a number of LEDs mounted to circuit boards, wired to drivers that were clumsy at best. The complexity of LEDs in the earlier stages were compounded by the lack of available components, which meant one-off application of the technology was out of reach for anyone not up for custom electronics design. (more…)

To set things off on the proper foot – I do not like complexity when it is not necessary. I’ve noted many times that if energy were free and maintenance was not a consideration, the perfect light source is the tungsten halogen lamp. This technology delivers a very attractive white light, is very easy to control, provides optical focus, and is as simple as it can get. The low voltage versions of this technology are equally attractive, accepting that transformers were a horrible thing to tag onto an otherwise neat little light source. I have made hundreds of lights using halogen lamps, mainly 12V versions, starting back in 1985. It was my go-to light source. I still have boxes of transformers and sockets, acquired over years of making lights for myself and others.

Applying LEDs in efficient lighting designs is no more complex than use of any other source, just more productive.

Applying LEDs in efficient lighting designs is no more complex than use of any other source, just more productive, and attractive than CFL or other conventional “efficiency” improving sources.

That said, there is no escaping that energy is an issue, and maintenance is a pain. The cost of operating halogen technologies is simply impossible to bear. This is why we have HID sources with all their ugly liabilities, and the fluorescent lamp.  While I get HID technology as a giant super-power halogen device, it has always been a clumsy, heavy, messy engineering gadget that sets aside the art of lighting for raw lumen energy. Fluorescent lamps have are a source you are forced to live with, in an uninspired, just-get-lumens-in -the-box sort of way. There is very little to love about their scale, lack of focus-ability, ballast hardware, delicate tubes, and ghastly glow. I’ve specified millions of these lamps into existence, wishing every time there was a better way. I never made a single art light using fluorescent lamps, not because itsn’t possible, but because I never liked them enough to give them that part of my time.

The emergence of solid-state lighting, specifically LEDs, hit me in two ways. One, I get the small controllable source I had with 12V halogen. Second, I get the efficiency and raw lumen potential of fluorescent that made it indispensable. Because of this, the last time I made a light using halogen technology was in 2004, and that product was converted to an LED sources in 2006. For my own use, every halogen light I made from 1993 to 2004 still in use around the house, has been converted to LED. Every new fixture made since 2005 has incorporated an LED light source, without exception. I do not use retrofit lamps. I either tear down and rebuild products to utilize LEDs properly, or design them around LEDs in the first place. (more…)

The Replacement Dichotomies

Side One: It is acceptable, if not desirable, for LED luminaires to be replaced at the end of their service life. This is a common position among a wide range of LED product manufacturers. They make the case that extracting performance and costs from LED products requires a level of integration that cannot be accomplished using modules. This further forwards to concept that modules restrict design freedom, that integrated products are free to create light source forms to suit the intended end-product design, without restriction of standardized sockets or modules. Therefore, it is proposed, that the highest performing SSL products will be integrated units, replaced at the end of their life with the next generation of even higher performing product. The model often used to illustrate this approach is that of televisions, where the entire units are replaced, rather than serviced, with newer generation products.

Side Two: The single most active market in solid state deployment is that of the direct lamp and fixture replacement space. This includes screw based lamps made to imitate the light output and distribution of obsolete technologies, and extends now to bi-pin linear forms to replace fluorescent sources. Oddly enough, the one lamp form that is not addressed, is the one most universally despised in commercial and residential markets alike – the plug-in CFL lamp – but let us not be distracted by this obvious and blatant oversight.  This replacement lamp direction appears to make the statement that the existing infrastructure of sockets is not replaceable, that demanding building owners and end use customers to replace existing fixtures is a burden beyond acceptable limits. This also forwards the concept that the existing socket forms within compromised products, is acceptable, regardless of its severe negative impact on SSL product performance, design freedom and appearance. (more…)


In an effort to create the highest possible performance in a portable lighting product, assembling the right combination of components is essential. Obviously the process begins with an efficient LED suited to the lighting effect desired. The LED must then be matched with an efficient driver. Finally, the driver must be fed power from an efficient power supply that converts incoming AC line voltage to clean DC power. Efficiency is generally found in matching the load of the LED to a driver designed for that load with no necessary over-capacity. Then, mating the driver to an efficient power supply matched in size to the driver’s operating load is necessary to produce the highest combined efficiency. (more…)

Photo from Philips Press Release

When the electric lamp was introduced at the turn of the century, the first push for product was to create retrofit kits for gas lamps. They ran one wire down the pipe and used the pipe steel as the neutral/ground. The first fittings screwed into the gas lantern where the mantle and burner mounted. This was seen as an important first step. So was the business of creating new electric table and wall lamps that looked like candle holders, oil lamps, and gas lamps from lanterns to shaded products once shielding a glass enclosure for the flame based light source.

In 110 years since, the commercial market has abandoned all of this to use the new technologies, from incandescent to fluorescent and HID, in new product forms enabled by the technology. This is why the commercial market today is reasonably efficient, given the state of the source technologies in use. It is also why most commercial lighting will be all new product designs using SSL in new ways. While it seems retrofit PAR lamps are a good fit, in fact, most lighting upgrades are installing new products, dedicated LED product, from cove lights to display, and recessed down and troffer lighting. Most commercial products today could not exist within the limits of gas lighting, while even more cannot work without fluorescent or HID. Soon, there will be a growing range of SSL product not possible otherwise – as it should be.

On the other hand, pandering to the residential market has produced a condition where the design vocabulary remains founded on retrofitting of gas, oil, and wax light source technologies. Table lamps and sconces today in this segment would look as home in 1889 as they do today. Retrofitting these exposed lamp products with CFL has been a disastrous mix of  bad performance and horrible lighting quality. Retrofit versions of one of the only new designs to strike residential – the ceiling bent glass light – is truly awful when lamped with CFL. <br><br>I am amused and a little bewilderment that we are going to use LEDs to retrofit the electric lamps that are just retrofits of gas and oil lanterns. This causes consumers to make the direct comparison in the exact same fixture, between two technologies of completely different lineage, often resulting in dissatisfaction. Part of the failure of CFLs as retrofits, is they cannot stand up to a direct comparison with the beloved incandescent lamp, in the same product, side-by-side. New products that offer  no direct comparison, allows the new technology to deliver new value, on its own terms. The incandescent lamp is a wonderful light source, if you ignore life, fragility and energy use – which is exactly what the residential market has done for 50 years. LEDs will never produce an exactly equal one-for-one replacement, they will always be compromised as a retrofit, as the retrofit architecture compromises the technology to fit an obsolete form factor. However, there is infinite opportunity in deploying SSL products that beat incandescent lamps for light quality and aesthetics, that make the old burner lamps look like big black phenolic rotary phones.

Consumers replace old products all the time, of value well beyond that of table lamps and a few sconces. From phones and entertainment gear to cars, furniture, and homes (average stay is just 7 years, so there is no truly inseparable connection between the content of any home building), pressing for a replacement of the old lighting junk, only delays adoption. Manufacturers should be focusing on deploying products that entice customers to move from their old obsolete product to new and better energy efficient products. This has been played out in the telecommunications market, entertainment market, electronic game market, computer market, automotive market, etc… It can be put in place here, if that is made the focus. In street lighting, the leading solution selected is all new LED street lights, not retrofit lamps – for good reason – it is the best approach. Same applies to garage lighting, down-lighting, cove linear lighting, display case lighting, and a growing range of new SSL products being installed to replace obsolete incandescent, fluorescent and HID products. Change is not an issue – when it delivers good value. When retrofits are seen as the preferred solution – this indicates a failure of the market to deliver lighting products of greater value than the compromised retrofit solution.

It my own view that the money being offered by the government as a reward for creating a direct replacement lamp should be spent in stead on awarding manufacturers who innovate new and improved high efficiency lighting to replace incandescent products of all types, including delivering new products that satisfy residential aesthetic interests without continuing a third generation legacy of obsolete light sources.

I respect those pursuing quality retrofit lamp offerings, and accept that my views are not yet widely shared. However, that does not mean I agree with the approach, or promote it as a valid or desirable approach, as there is no such thing as universal truth. We should all feel free to pursue this transformational period in any way we feel is the best fit. In the end, what wins will be what sells, which will likely be a broad array of product from retrofits, to all new products that change lighting in some way.

The sooner we take on the task of moving from horses dragging wood wheel carts around dirt roads, and look ahead to putting SSL to work in new ways to deliver exciting new value, the sooner the interest in retrofit lamps will fade – just as the interest in rabbit ears on console televisions, 8 track tapes, pong games, and stand alone PDAs has. This takes a concerted and focused effort, not a short sighted vision using seemingly easy paths.

Think about this: As we discuss this issue, recognizing that the incandescent lamp is obsolete, the availability of retrofit lamps is enabling decorative residential product manufacturers to continue to make, market, and sell all new products with Edison sockets. With no pressure to change, and plenty of excuses not to, when exactly do we make the real transformation from one technology to another? While fitting retrofit lamps into valuable legacy products does make some sense – allowing new products to continue and advance this as a new product approach is ridiculous.

For these reasons, I do not directly support, nor do I support my tax money being spent on subsidizing, the advancement of retrofit lamp deployment as a priority. If it is going to exist, it should do so on its own as a short term patch, with every other effort focused on moving forward, encouraging manufacturers to move away from obsolete platforms, and rewarding innovators for leadings us into the future.

The challenge is not getting consumers at all levels to swap light bulbs in familiar products – the challenge is in creating new value that is irresistible to them, that causes the market to abandon its familiar obsolete products to capture this value for themselves. This will not come from clumsy fix ups and compromised solutions.


I am personally exhausted with the constant barrage of PR hype clowns that have invaded the entire SSL market space, it’s like a bad virus that feeds on active brain cells like some zombie brain eating monster that insists on howling at the top of its lungs whenever it thinks its done something interesting. The lighting market has always had a little bit of a stomach pit inducing illness, with claims made that are silly and obviously not founded on the reality normal humans are forced to exist within. However, what has been happening over the last 5 years coming from the SSL universe is an all new illness, it’s far more aggressive, and more painful.

Part of this is due to a change in paradigm regarding marketing. In the past, lighting companies employed in-house marketing people, who used local marketing agencies to place ads, or do some graphic work on catalogs. I know, as this is the function I performed for three leading product manufacturers for almost 20 years. We communicated to our target audience through reps, catalog sheets, web sites, trade shows, and an occasional letter campaign. Few actually used big PR agencies with broad marketing campaigns aimed into the wind. Know why? Simple, they are really expensive, so were never even considered as affordable, let alone useful. Most have zero knowledge of the market, think that that lack of knowledge is not an issue, and cost more for a few press releases than most total marketing budgets for an entire year. It takes the funding of venture capital to back a company with the funds needed to spend what they do on PR, while at the same time producing the need to broadcast their message to the world at large to support investors who are outside this market. The result, we now have a pile of non-lighting PR agencies with bullhorns, blaring whatever their customer companies (also non-lighting people) tell them is news to our once relatively quiet lighting world. The resulting din is akin to a neighbor who can’t seem to listen to music without cranking the dial up on an expensive amp to “11”. To make matters worse, the music selection is like bump-bump rap, the same noise, over and over and over, drumming and pounding messages of efficacy world records and earth shattering performance that will save the planet from certain destruction by incandescence, and fluorescence.

To make all of this even more painful, is that this virus is unpredictable. One day I get pounded with three releases that when exposed to the light of day squirm off the screen and hide under a table.  You’ve seen them, the claims of a 12W LED product with a CBCP of 4,000, and 800 lumens beating a 70W Ceramic Metal Halide producing 22,000 CBCP and 2,100 lumens – or the claims that the LEDs used will last a lifetime, or that if everyone used the product, our teeth would become whiter, and our skin smoother. Anything goes here, from claims of efficacies of 180 lumens per watt (at some stupid CCT), to performance comparisons that are simply fiction no matter how you look at it. Then, the next day, you get an interesting release about a color control system that, well, oddly enough… actually provides something useful and interesting. Unfortunately the ratio of garbage to inspiration is heavily weighted toward the landfill side of the formula.

The cultural shift that surrounds solid-state is not founded on anything the electronics gurus believe. Contrary to the impression that we are slow-witted laggards, we lighting people will absorb and put SSL, to use,  just as we have every other useful technology that has come before it. When the SSL providers actually produce lighting product (not just the LEDs, not just an electronic gadget, but a real live luminaire product) we will find uses for it, IF it works, produces a benefit beyond just using LEDs, and if the price makes sense in balance to the benefits realized. By this, I mean benefits in lighting terms, as we define it, not in terms of PR baloney, engineer pipe dreams, or marketing department trickery – I mean in real terms, using real data, real photometric tests, etc… The electronics gurus give us too little credit here, and don’t see where the real culture clash is founded – a huge difference in the perception of money.

The difference between an SSL start up and a lighting industry start up is spectacular. The vast majority of lighting industry startups began from the personal checkbooks and savings accounts of individuals, who worked their way into a market one step at a time, sometimes failing, sometimes succeeding, and rarely with much fanfare from expensive marketing entities from New York or Chicago executive towers. We are talking about real world, grass roots, dirty hands startups. Solid-state startups, at least by the time we see them, have a lot more money at hand… a lot. Most have more cash from venture capitalists than most lighting company startups realize in total sales after 20 years of effort. Having a starting fund of $20M is not unusual in an SSL startup, while I personally know of dozens of lighting manufacturers who started with less than a few thousand, scraped out of personal savings.

The result of all of this, like the invasion of South America by the Spaniards, is the spread of SSL Hype Clown Virus. A lyric from a recent Pink! album (Funhouse) illustrates this well… “This museum’s full of ash, once a tickle, now a rash… this used to be a fun house, now its filled with evil clowns….” Unfortunately, behind all this overly aggressive and ridiculous press is a population of really creative technicians, who are making strides and inventing new things we will all come to put to work. It’s kind of like having a best friend married to a loud and obnoxious partner – in the end you avoid them both to maintain sanity. There is a part of this happening in the adoption cycle of SSL. There are more than a few potential customers who are so sickened by SSL HCV they can’t see the great technology behind it.

There needs to be some effort to vaccinate this market from the most aggressive forms of the PR sickness. This can only come from the solid-state providers themselves, reigning in what has become a real evil-clown parade, leaving behind horse apples and associated stench. We lighting people are not going to respond to this positively. We have heard so much trash talk, been promised the impossible, and seen so many ridiculous claims, that we’re becoming deaf to the noise, reducing the effectiveness of any releases going forward anyway. Might as well try a new angle – clarity, realistic statements, backed by independent test results and data we can all put to use. Fire the high power marketing agencies, spend the money on more product, and communicate to us all like the professionals we are.