I have several fresh and brewing ideas about office lighting, putting new technology to work to make sitting in our little prisons more enjoyable and healthful. To put these ideas in context, and to consider real-world application nuance and detail, I’m collecting images of actual office spaces from anyone will to share.  I don’t need great pictures, just a quick snap with a phone that shows as much of the space as possible, perhaps with the lighting visible.

My office also houses the 3D printers. They need the clean/warm space to work best, and I like having them close.

My office also houses the 3D printers. They need the clean/warm space to work best, and I like having them close.

If you have a moment, include any comment you might have about what you hate about the space, and the lighting, and perhaps what you like most? The spaces don’t have to be all cleaned up and tidy, in fact, the mess tells me as much as the arrangement.

I promise the images will go no further than a folder on my hard drive for reference in creating illustrations of model spaces within which I will be laying out alternative approaches and lighting products that might be applied.

You can do this all in less than a minute with a smart phone by sending me a an image to 414-241-5124, or kwillmorth@lumeniuque.com. I’ll send you a look in the future to what came from the effort, giving anyone who participates an inside peak of what I came up with and why.

Thanks in advance to all that participate!


LED Color Viewer

Posted: August 10, 2016 in Uncategorized

We’ve been working for several months on an LED Color Viewer that is easy to use, affordable and portable for use in the office and for taking it to client offices. Well, we’ve finished it at last.


The viewer contains 5 Cree CXB COB LEDs in 2700K, 3000K, 3500K, 4000K, and 5000K, each rated at 90CRI, that are selected with a simple selector switch. The viewer also includes a dimmer, so you can see the effect of light level on color. A rocker switch allows the light to be turned on and off without disturbing selector/dim settings. The viewer is easily folded up for storage and transport in an included carry case, which is padded, and includes room for the cord, as well as a pocket for taking along various color cards. It’s a perfect companion for the samples room, as well as viewing print media by graphic designers, and study by lighting designers when making presentations to customers.

The viewing area is 17″W x 13″D. x 12″H. The side panels are easy to clean, and are hard plastic for taping on materials, easily removed. The hinged design is simple to set up and take down, as we show in the video below:

The viewer is made in the USA, and includes the carry case. Each viewer is measured for CCT, CRI Ra/R9 and TM30 Rf/Rg, with exact results shown on the top of the housing for reference.

This will is offered on the Tasca web site for on line purchase through the Lumenique Product Center for $650, case and shipping included: LED Color Viewer


June and July are not only the first nice days of the year, they mark several milestones for me. First, its’ the 10th year of Lumenique LLC being focused exclusively on solid-state lighting – marking the point at which I left my last position as VP of Marketing and Design at Visa Lighting in 2006 to focus on all things solid-state as a solo act. Prior to that, Lumenique has been many things, from hobby presence and sculpture studio, to lighting consulting side business. This last decade is its first as a focused entity and source of real income. 6 years ago, I launched a task lighting product line, under the name Tasca. I am a serious task light advocate, and build Tasca products for the tougher applications, like shop machines and Navy ship bridge and map tasks. Most of the products we make at Tasca are custom to a specific requirement, either mounting or light characteristics. This will be a greater focus in coming years, as there are many opportunities in task and work lighting I’ve found interesting.

It’s hard to believe that its been 6 years since the 52 in 52 project. I don’t post here as frequently as I did back then, not from a lack of interest – I just get wrapped up in what we’re doing day by day and find that times slips past.

Lumenique continues to focus on providing specialty product design and development, prototyping, and experimental approaches. Over the years we’ve moved toward making more things over selling time, but still have several consulting customers at any given moment. It’s a diverse business that has only become more diverse over the years, which makes life most interesting. Angie joined the fray three years ago, and is growing her capabilities in product making, research, and general backup. The company is our focus now, and we enjoy working on it together.

This also marks the 10th year of Architectural SSL magazine, a publication from Construction Business Media, who also publishes Architectural products and now NZB magazines. I am honored to be counted as one of the team, they are a great group of people that produce the highest quality publications in lighting and building markets. We were the first publication to focus on architectural solid-state lighting, and I believe remain a unique voice in the market, while providing exposure of the expanding array of products coming to this market.

2016 also marks the opening of our new facility, where we have room to work and expand our capacity to serve customers of products and services alike. In just six months, we’ve already been hired for contract production and assembly, and are on the verge of introducing a couple of specialty solid-state products for uses outside lighting itself. Business is good, but as anyone who owns their own gig will tell you, it can always be better. We’re constantly exploring new ideas.

So, in the last 10 years, there have been many players in this business come and go. We’ve seen the solid-state market grow from silly low-performing, over-promised toys to the robust performance products of today. It’s an exciting industry, with much more coming!

Thanks to everyone who’ve sent us anniversary congratulation notes.

Bridgelux has announced the End of Life for the BXRA product. This is the product that put this company on the map, and has been very popular. The company is now hawking its me-too product platforms, along with its proprietary Vero product. I for one will never again consider a proprietary platform from Bridgelux. I am also sure they will experience a significant number of defections as customers find their way resolving the disruption the end of the BXRA platform will cause. I know this, as I intend to help every customer of mine, and anyone else interested, to find a path to other provider products.

When Bridgelux came onto the market, it professed to know the architectural lighting market, making bold statements about how it would support its customers with consistent products with little or no platform obsolescence. O bought it. Cree has done this, so it was no stretch to believe Bridgelux could make good. They were also touting themselves as a U.S. company, invested in the U.S.A. Yet, over the last several years, they have proven that all that blather was just marketing farf. They’ve made regular product changes that have demanded redressing driver selections, not to mention changes in fV and max current limits that have fouled up UL listings. They have walked out of the U.S. market as a manufacturer. Now they are owned by the Chinese CEC company, and have completely turned their back on past promises to serve their customers with the product stability. I have promoted this company to customers, and use it in my own Tasca products. That ends with the demise of the BXRA3.

At the core of this seemingly small issue of planned obsolescence, is the impact these changes will have on hundreds of customers, effecting thousands of end products, including UL and photometric test implications that will result in a lot of cash being spent in response to this discontinuance. The underlying issue is that BXRA ES and RS arrays once presented a unique combination of voltage and current that created unique driver configurations different from their competition. For most, changing to any other COB will require redressing driver selection, which will demand UL changes. For some, the implications are going to be significant. For example, in some products I am directly involved with, the power supply is 24VDC, with buck CC drivers connected to the LED. That is no longer possible using any of the new COBs from Bridgelux. Cree, thankfully, has a few options that will limit the damage to some degree. For others, the open circuit voltage of higher fV drivers will create a mess with LED holders that have exposed metal contacts that UL will insist be covered, demanding changes that will likely lead to re-testing. And, for many, the impact on optics is going to be a long and hard road to travel. Changing the array to a new platform will require new optics be sourced, and since these are not exactly the same as the outgoing combination, new LM-79 testing will need to be done. This is all going to have to happen NOW, as the announced EOL is immediate, with the last products available for order in mid June.

The saving grace in all of this is that the replacements Bridgelux offers are not significantly unique in voltage, current limits, lumen output, color, or general size/configuration from what is available from many others today. That means that when customers are faced with the disruption of re-configuring their products to the higher fV/lower current requirements,  and new optics, they can consider pretty much all competitive products to protect themselves from any future recurrence of changes in any one proprietary configuration the end of the BXRA platform presents. Since the new configurations will require updates, if not completely new UL testing, and likely new photometric testing, I strongly recommend that every Bridgelux BXRA customer cross their requirements over to at least three providers. Cree, Samsung, Citizen, and Luxeon now all make very strong performing products that can stand up against anything Bridgelux offers – with the same core fV and current combinations  to attain equitable output. This, combined with the range of Zahga compliant LED holders and associated optic accessories, pretty much means the proprietary Vero series is a non-starter – except for those that are Zahga compliant.

I personally will not update with Bridgelux new products. For my own products, we are black-listing Bridgelux for its inconsistency between what it says it is doing and going to do, and what it actually does – often with very short notice given. My continued strong support for the company ends with the BXRA platform EOL. It is the perfect opportunity to break away from them and move forward with new providers, and I intend to take full advantage of that. This saddens me in some way, as I have had so much fun and enjoyed building products around the BXRA. This is the end of a very short lived era for me.  When Lumileds ended the K2, the backlash was severe. I expect that Bridgelux is going to experience much the same with the ending of its BXRA ES and RS arrays. I’d wish them luck, but can’t find it in me to be that polite. This situation stinks, on so many levels that its hard to be calm about it. At a time many are finding their feet after being pounded by the cost of SSL development and a soft economy, to now face redressing products already in demand and on sale, caused by manufacturer planned obsolescence – means nothing of value is gained, and a lot of unnecessary cost will be incurred.


I propose that all pursuits of a color quality metric represented in any form of numeric value based on averages of performance over any number of color samples is wholy inadequate and a wast of time. We have been using such a system for far too long, with too many questions and related surrounding quality issues unanswered to continue with such a weak approach. I suggest that we pursue a Lighting Qualities Classification system that encompass eight (8) core variables that are critical to identification and selection of lighting products. This would be represented in a similar fashion as the successful Ingress Protection (IP) rating system already in use.

My concept is that there are three core categories of concern that lighting customers and specifiers want answers to in an easy to use and apply form. These are Uniformity, Color Quality, and for some, Human Factors. A color quality standard, as we already know, is meaningless if uniformity is not known. The current and all proposed metrics for lighting quality also fail to deliver any insight into color tonal shifts caused by Duv, and do not indicate or suggest that all sources of identical result are going to be uniform in appearance. This proposed LQC classification system addresses these issues, representing lighting product performance using data already available from current test results, in a manner that can be applied to select appropriate products for application.

Here is my first raft concept of the LQC classification in a table format, similar to that used to define the IP rating system:

LQC Rating System Table

LQC Rating System Table – Proposed Draft

In this classification system one can expect:

Uniformity Performance – Products from a range of manufacturers, or individual products from any one manufacturer, with a classification of 5 will deliver uniform appearance, while the greatest variations will occur in products with a classification of 1.

Quality Performance – Products from a range of manufacturers, or individual products from any one manufacturer, with a classification of 5 will deliver uniformly high color fidelity, minimal saturation effects, and strong color rendering over the complete spectral range, while the greatest variations and lowest color rendering results will occur in products with a classification of 1.

Human Factors Performance –  Products with a classification of 5 will deliver optimal human visual performance, while those with a classification of 1 will deliver less than optimum performance. This is an optional classification (like the thrd value in the IP rating for impact protection) recognizing that in some applications, human visual performance, either for acuity or to optimize energy use, is not a priority – such as high end hospitality where warm sources and mood/appearance are the primary drivers.

Based on this, decision makers can pre-qualify products based on application needs and requirements. Just as an IP67 rating is unnecessary for 100% of applications, an LQC555 product is not a universal requirement. Here are some examples of application of this LQC classification system:

Parking Garage Lighting – LQC124 will produce a product with minimal attention to uniformity, a good color rendering quality (for identification of color), and a high human factors performance level to optimize energy use and visibility.

Classroom – LQC445 will produce good uniformity, high color rendering performance, and strong human visual system support for learning environments at a reasonable economic level.

High End Retail or Museum – LQC55, or LQC553 will produce maximum uniformity, maximum color performance, and acceptable human factors for the application using warm color sources (optional classification).

Residential – LQC442 will produce a product that suits the majority of fussy homeowners and represents the human factors likely to be available when using warm color light sources

Critical Task and Inspection Lighting – LQC555 will produce maximum performance in uniformity, color and visual performance.

Low Activity Storage (low color demand) – LQC11, or LQC111 will support the most economical light sources and indicates a minimal need for quality over cost.

High Speed, Low Color Demand Task Application on a Budget – LQC115 might be applied,  utilizing TM-24 methods to reduce energy consumption through application of enhanced visual performance, with lowest cost products as a priority

I recognize that a classification system of this type requires more refinement. However, I suggest that this is a robust approach that with minimal understanding, manufacturers can apply this to market products toward specific intended application, while decision makers and designers can select and communicate their requirements through specification of a desired or necessary classification for the intended application.

The application of this type of multiple factors classification system encompasses the core concerns of decision makers,  answers questions not now being delivered, removes the need for decision makers to attempt to hack together evaluations based on data that is not always readily available, and builds a foundation to build products and identify latent demands that are now concealed by the virtual lack of actionable metrics for us all to work from.

Specifications could also be written around identification of a range of acceptable product classes within the three categories. For example, one might  need uniformity to remain very tight, where a specification of anb absolute “5” classification is set. However, that same specification may not require perfect quality performance beyond that, so a quality value might be represented as >2, or indicated as  range of 2-5. Meanwhile that same specification may consider energy efficiency as an important requirement, demanding a Human Factors classification of >4 or a range of 4-5 as acceptable. This opens the door to a wider range of products, from LQC524 up through LQC555 to be applied and offered by manufacturers.

Manufacturers can use this classification system to expose and promote their products performance and its comparison to competition. For example, a manufacturer that is committed to the highest uniformity in their product offerings, at the most popular quality levels, can state that all of their products deliver an LQC of 53 or better, while specific offerings targeting the human factors market space can be promoted as delivering an LQC of 534 or greater, indicating the only area of variability and performance selection is choosing a color metric that fits the application.

Just as the IP rating system is more descriptive than the UL Wet and Damp labeling standards, the LQC classification reaches beyond simplistic single aspect lighting qualities of CRIe or TM30,  that are now creating more questions than answers.


Zero Flicker Task Light

Posted: January 21, 2016 in Light Meters, Tasca
Tags: ,
The Tasca task lighting head. My pet project for more than 6 years now.

The Tasca task lighting head. My pet project for over 6 years.


When I created Tasca, I had several goals in mind:

  • Strong light output  – Check – 800 lumens is top of its class
  • Smooth wide light pattern – Check – 78 degree beam pattern with no hot spots, no streaks, no rings, >200Fc at 18″
  • High color performance – Check >80CRIe standard @4000K, moving to >90CRIe @4000 or 5000K in latest models
  • No sparkly LED arrays – Check – single high quality COB array source
  • High efficiency – Check – >70lm/W total fixture efficacy
  • Tough and Ready – Check –  examples have been in operation 24/7/365 in shop environments with zero failures
  • ZERO FLICKER – Check – see below

During the development of Tasca, finding a flicker meter was a little tough, so I improvised an oscilloscope and photocell rig that allowed me to see light output modulation. Using this we experimented and tested combinations of LEDs, drivers, and power supplies. I felt the end result was pretty much spot on, as near to the zero flicker from battery operated sources or even daylight as one could get. Yet, until recently, I had not been able to verify this was the case. Enter the UPRtek MF250N flicker meter (review to follow soon). With this, I have finally been able to see how well the Tasca head was performing. I was thrilled with what we found.

The Target

Daylight and the DC LED ideal models to set a high bar.

Daylight and a DC powered LED were set up as our performance target. They simply don't flicker, so using the meter, I tested these bench marks.

Daylight (left) and a DC powered LED (right) were set up as our performance target. They simply don’t flicker, so using the meter, I tested these bench marks. Note that small aberrations in readings (like the frequency of 5 for daylight along with a frequency magnitude of 2.6, or the frequency magnitude of 0.6 with no frequency for DC connected LED), are just that. This happens in all metering to some degree, and are within a margin of error for this meter system.

The Tasca Head Result

The results speak for themselves.

This is Tasca

The results for the Tasca head are exactly what I’d expected. Their simply is no flicker. While the meter indicates a Flicker percent of 000.6, and a magnitude of 0.2,  there is no frequency component, so these are irrelevant.

I was thrilled with the results. It meant several things. First, these metered results were essentially identical to what we got with our shop made flicker measuring rig. Second, the product itself is simply doing exactly what I intended it to do, which is truly satisfying.

Comparisons for Fun and Perspective

As long as we had the meter out, I figured why not get a few more readings for comparison. The results:

This is a T12 on magnetic ballasts. The beast that started the flicker discussion.

This is a T12 on magnetic ballasts. The beast that started the flicker discussion. The wave form shows obvious modulation, supported by poor results in both flicker % and index. The height of the wave shape is evident in the VFMA (Flicker Amplitude) and FMag (Magnitude) readings as well.



LEDs connected to AC circuits are not a good thing, even this one using additional bits to supposedly reduce flicker. The results are the highest flicker % and Flicker index of any source in this comparison, in every measure.


Capacitor AC LED

This is an AC connected LED with big capacitors added in an attempt to fill the gaps. While it reduces the flicker index to some degree, it has no effect on the flicker %, while the odd wave form creates strange results in other areas.


This is a retrofit LED

This is a retrofit LED. In general, it does not do a bad job reducing flicker, but is obviously playing a trade off game between cost of driver/power supply and output modulation.



This T8 fluorescent with electronic ballast is doing a nice job of controlling modulation, with a very small, impossible to see modulation at the native 120Hz.

P.S. Notes on the Flicker Argument

I recognize that there is a grand debate about flicker and whether or not it is an issue at all. Most of the argument against setting strict flicker standards are put forth by those who seek to market low cost LED products that exhibit flicker of 120Hz, whether that be AC LED product based or just low end power supply components.

There is no case to be made that flicker is a positive component of lighting, and extensive past industry experience with T12 fluorescent lamps on magnetic ballasts, and HID sources used in commercial application, is what started and fueled the discussion of 120Hz flicker as an issue. Complaints of visible modulation, headache, migraine, etc.. have been studied and found to be corollary to  the existence of flicker. Further, studies have proven a connection between flicker below 200Hz having a negative effect on visual performance in schools. While it is true that organizations like NEMA, IES, CIE, and IEEE have yet to come to an agreement as to what defines bad flicker vs. acceptable flicker, this lack of agreement does not indicate there is no issue. In fact, that these organizations have and continue to discuss this issue, against the steady pressure of manufacturers to set it aside, is an indication that there is a very real issue with flicker, that will eventually be resolved – albeit with some compromise included to placate manufacturers involved in standards proceedings. As a member of the IEEE 1789 committee on the topic of the risks of flicker, I can attest to the depth in which this topic has been investigated and discussed, and bear witness to the hundreds of papers written on it and its effects on vision and human physiology.

In my own opinion and recommendations to others, I ask one question – If there are sources and products available that exhibit no flicker, or flicker of such character as to not be an issue (such as T8 and T5 fluorescent on electronic ballasts, and quality LED driven products), what is the reasoning for continuing to accept any products that flicker in the zone of 100Hz to 200Hz, with a flicker amplitude >0.3 (minimal modulation depth) at all? Any level that exceeds, approaches or shares flicker characteristics with the T12 fluorescent lamp on magnetic ballasts, in my opinion, should be considered unacceptable for any use, regardless of arguments over cost saving. This includes any continued use of magnetic ballasted HID sources for interior illumination and AC connected LEDs (with no flicker mitigation) – as these are all far worse than the T12 lamp.

While in ambient lighting, a weak case might be made that flicker may be of small consequence – I propose that in task illumination, where visual acuity is critical, focus is the goal, and high illuminance and task demands increase the risk of stress, there is no rational case to be made to accept flicker of any level. For this reason, I have focused my attention and effort on creating lighting systems (and sources for components) that present either no flicker at all, or characteristics, such as high frequency operation (>2,000Hz), very low modulation depth (amplitude of <0.3%), low flicker index (<0.05), at all light level settings or dim states. I believe these to be reasonable and attainable standards, and have found no reason to accept poorer performance.

In the discussion of lighting quality, there appears to be a desire to see a simplistic set of performance factors to be met, that can be universally pointed to as “quality”. This is most apparent from fixture manufacturers, who wish to have a set of 3-5 reductive bullet points to indicate their product is a “quality” product. Color rendering is one such factor frequently singled out in this effort, regardless of its relevance to an application.  A quality lighting system is more than the sum of products lumped together into a specification, each defined as quality components, without contextual inter-connectivity. Lighting quality is the result of creating a recipe of approaches, priorities and understanding/agreement that delivers a system that satisfies the end-user occupants, the facility operator, and external influences  to the highest practical level. To this end, I have attempted below to summarize, in the most reduced form possible, the systematic factors that define a quality design.

There is no magic formula for lighting quality.

  • Quality of applied lighting approaches/systems are defined by room by room, that establish approaches to:
    1. Lighted spatial appearance, image, aesthetics
    2. Glare/brightness control
    3. Color selection and performance factors
    4. Natural and artificial light integration
    5. Visual performance support and enhancement
    6. Time and space connectivity and relationship
    7. Controls operation and function
    8. Energy use and efficiency
    9. Operational commitment – short and long term
  • Prioritization of lighting qualities requires careful evaluation and consideration of the following considerations:
    1. Practical needs of those occupying spaces
    2. Type and character of visual tasks involved
    3. Human factors (demographics, condition, etc.)
    4. Desire to support/enhancement human health
    5. Sensitivity to flicker and/or color variation/distortion
    6. Comfort of occupants
    7. Available budget (energy and capital) initial and operating
  • To deliver a quality lighting system/solution within the priorities and approaches defined above requires:
    1. Recognition that energy efficiency is not a quality of light, but it is a component of a quality lighting system
    2. Understanding of both the visual and non-visual effects of light on humans
    3. Understanding that the subjective and objective measures of quality are defined by appropriate application within established priorities and goals
    4. Recognition that human occupants are not singular entities that can be lumped into averaged assumptions.
    5. Understanding that the visual environment is a blend of objective need, subjective perception, and practical limitations that cover a broad range of requirements and perspectives.
    6. Realization that “lighting” quality factors must be resolved in concert with non-lighting features within spaces that enhance or detract from quality lighting in isolation.

Within each of these reduced descriptions lies a depth of detail that can be applied depending on the level of priority established. For example, for a space focused on task accuracy, consideration of human factors would require digging deeper into age range, physical condition, etc… to establish the demands on task lighting and the need for flexibility to accommodate the range of occupants anticipated. The dynamics of design may also place all of these factors in whatever order is appropriate to establish a quality end product in context to the practical definition of the project involved.  In truth, the most important factor in realizing a quality solution is the quality of the approach taken and how completely it includes consideration of the range of factors, considerations and priorities involved. The more superficial an approach is, the less likely the result will be of high quality. This does not mean that quality designs need be overly complex, or time-consuming, it just means that a conscious effort to balance these considerations is what defines a quality end result.

While we might all agree that glare control is important, in some applications selecting the lowest glare product may be less important than selecting a higher efficiency product. Glare is also dependent on viewing angle and movement dynamics that cannot be universally represented by a set of features defined as “quality”, outside the context of application. High color quality is not a universal requirement – ranging from highest priority to nearly irrelevant in low demand transient occupancy. Enhancement of human visual performance can be critical in high demand tasks, yet be of minimal value in low demand transient spaces. Lighting for visual effect is meaningful for some applications, or generally irrelevant. Human factors, such as supporting visual performance, as well as mood and health enhancement factors, are naturally a component of all lighting systems designs, as lighting exists for human consumption, with no other purpose beyond this context. However, the degree of effort invested in enhancing the human experience varies greatly, from critical to merely supportive. For these reasons, and many more, lighting quality cannot be reduced to a simplistic set of universal factors, out of practical context. Lighting quality is achieved through prioritization and spatial end use delineation that establishes factors that, when met, define a quality solution and end result. The deeper one digs into the needs of end users and how light effects them, the greater the opportunity there is to create a quality experience, thus, defining a quality lighting system.