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Solid-state lighting presents many opportunities to create fidelity in specification of lighting not practical or available before. Further, the blend of aggressive marketing, hype, and deception on the part of solid-state product manufacturers demands more diligent specification than ever before. The days of the conventional mode of specifying luminaires and lamps as two separate components, with experiential trust in both, is over. Today, luminaires and light sources are integral to one another, often offered up by those who have marginal experience, and a strong desire to realize sales. The only defense against predatory and overly aggressive marketing is to understand and develop a strong specification foundation. The next protective barrier is to hold that specification. The following are suggestions for building a solid-state lighting foundation for any luminaire specification, with rationalization for each consideration in practical terms. (more…)

After reviewing a range of different metering choices in actual use, I compiled a summary of findings, as well as my own personal subjective ratings of features and overall utility as a lighting professional. This chart is the collection of all findings in a simple comparison table for those who find this useful (like me): (more…)

This is the Lighting Passport Flagship set. Includes case and accessories in a neat package.

This is the Lighting Passport Flagship set. Includes case and accessories in a neat package.

I first saw this device at Light+Build Frankfurt last fall. I was impressed enough to find one added to my collection of tools. The Asensetek Lighting Passport is a unique product in several ways. First, it is essentially a meter head (where the cost is), coupled to an iOS or Android device that does all the computational and display work. The lighting head has a nifty slide action receptor cover, so there is nothing to come off or get lost in a bag or pocket. The measurement range is as broad as any of the other spectrometers tested here, plus some. Not only does it produce the expected spectral power distribution, CRI, CCT, CIE 1931 and 1976 coordinates and illumunance in lux and Fc, it also delivers CQS values. (more…)

Okay, so while this is not of the same caliber, or as new and cool as the spectrometers, and could be considered an obsolete product, since it is no longer made – but, there are enough of these meters around in used condition, and they have been in use for so long, that finding one with the right attachments is not a serious challenge. So why bother? To start, the basic meter frame sold new for over $1,5000, with attachments to produce various readings. I found one example on ebay, sold from a test lab that was closing, that included several useful sensor heads. (more…)

The recent article: LED Bulb Efficiency Surges, But Light Quality Lags states very well the findings of the DOE and others reviewing LED retrofit lamp performance. While well stated, there are severl missing dynamic issues in the conversation that need to be included if LED is to overcome the failure of the CFL to capture the consumer market it so desperately seeks to dominate.

While efficient, there has been no great interest in the consumer market to lamps with poorer quality at higher prices.

While efficient, there has been no great interest in the consumer market to lamps with poorer quality at higher prices.

The CFL lamp has failed in the consumer market for these reasons:

  1. Light quality is poor in comparison to the far cheaper incandescent lamp. This includes color quality, distribution (photometric) pattern is poor (flood type products)
  2. Appearance and fit of the product into existing fixtures – i.e. ugly to look at, stick out of fixtures, create dark spots in shades and fixture diffusers, etc.
  3. They did not last as long as advertised. When switched frequently, the life of a CFL screw base product can be shorter than a long life incandescent. In outdoor cold climate environments, some fail within a few months. In down-lights and enclosed fixtures most fail even more quickly.
  4. They cost too much compared to incandescent of higher quality
  5. They save some energy, but have so many other liabilities the consumer does not take this seriously.
  6. Flickering starts, flicker under dimming, and 120Hz strobe effects from cheap ballast designs
  7. Slow to warm to full brightness – often taking longer to get up to full light than many products are on for in many rooms (pantry, closet, hallway, etc.)
  8. Mercury disposal concerns for some

(more…)

    Flex-arm-large

The Tasca test mule turned 2 years in continual illuminated state this May. That’s 8,760 continuous operating hours in the cold, hot, and messy environment of the shop in which it lives. It gets abused as well, from tossing greasy rags over it to see what happens when airflow over the heat sink is cut off, to blowing coolant on it until it freezes. There have been several lessons learned in this time. For example, lumen depreciation, captured by measuring the fixture’s output, has been negligable. Losses have been less than 1.2% so far, which means the White Optics reflector and anti-reflective glass are doing their job, as is the Bridgelux ES Array LED. Temperature readings taken over this time have not changed anywhere, which indicates the internal construction attaching the thermal slug to the heat sink is durable and reliable. (more…)

The problem with revisiting something one created many years ago, is that the underlying inspiration or idea has been lost in the winds of change we all go through as we experience ife, the universe, and everything. In my case, I even have a hard time relating to how the original “thing” was even made, having forgot what tools I was using and how I made things before I surrounded myself with tools and doo-daddery.

In the case of this weeks rebuild project, I had thought that a quick trip into the garage, slam through a few pounds of metal and viola! Finished update. Yeah… right. To really get a handle on this thing took drawing the whole thing up in 3D, so I could work through the ideas and concepts without making a mess of things. In other words, this little remodel job has taken more effort than a virgin design – in that it has involved starting with a reverse engineering of the original, then design of new component within the limits of its design vocabulary.

After several days of design and iterative thinking, I think I finally have a plan to proceed. The rendering is where I ended up. I like the almost alien quality of this lamp, and its odd semi-architectural structure, so wanted to make sure that was not buried in some over-thought, overly clean addition. I think this pulls that off. I’m going to fall back on use of (2) Bridgelux 400lm LEDs, as these will produce good light, and are easy to live with in color and soft edged pattern. I’m also employing a couple of finned heat sinks, that will be left black, augmented by some machined glare/reflector cups.1/8″ stgailess rods will replace the old saggy cables.

No, I am not sure about the clips at the glass, but that can be worked out as I get the rest of the parts made up.

Time to get to work now…