Lumenique – Inside Solid-State Lighting

A long time friend (and previous employer) decided it would be lovely to take his car apart and rebuild it from the ground up. I have witnessed my of these “projects” over the years – most end badly. Taking a car apart seems so easy. Just undo every fastener, and dump the parts that fall off into boxes – while tossing all those old rusty corroded nuts, screws, washers, broken little clips and pins into bins. When something is frozen up, beat it apart, or cut it, it’s all replaceable – right?

3D Printing is actually a misnomer. In technical terms, we are talking about AM (additive manufacturing.) The process delivers a 3 dimensional object in plastic or metal, layer by layer. Unlike CNC machining, which is technically subtractive in nature (starts as a block of material that is whittled into shape), AM produces no chips or cut-off material, just the finished part.

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The way we  access information is evolving. Where books and magazine publications were once the only reliable source of information, the evolution of digital media has blown some holes in the world of paper based media. By all indications, those holes are not going to heal, they are going to grow. The question is, will these holes tear the very fabric of print based information and advertising apart? (more…)

Recently commentary on certain news outlets, particularly friendly to the current occupant of the White House, have taken the stance that social restrictions are uncalled for and over-reactionary. To support their position, they state many examples of mortality statistics as proof that there are greater risks to health and well being than COVID19, that are not causing us to react at all.

These talking heads, and most of the statements they rely on, use of simplistic statements to defend a risky position. They are oblivious to the reality that in our slow reaction to (more…)

With the onset and spread of SARS-CoV-2 virus and the COVID19 it causes, I have seen many offer up the idea of using low cost UV light sources used primarily for curing resins and/or finger nail polish, as a method for sterilizing surfaces and used masks. Cutting to the chase… a $35 nail salon cure light is not going to work.

These sources use light between 365nm and 405nm, depending on the intended application. This is considered long wavelength UV light, or UVA (315 to 400nm). While these may be somewhat effective against some bacterial invasions, with extremely long exposures and/or very high intensity levels (well beyond those of a small cure light), there is no evidence this is a reliable sterilization solution for viruses.

To kill viruses, hospitals are now using UVlight robots that emit high levels of UVC radiation between 200nm and 280nm, and the primary germicidal range for UVC is between 254nm and 260nm, for periods of around 20 to 30 minutes – on top of chemical cleaning and sterilization procedures. The reason they use robots, is that this radiation is dangerous to human occupants, so is not done when anyone is in the room. UVC disrupts the DNA and RNA of micro-organisms, which prevents them from reproducing. Read Here for more on these machines and their use.

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The MacAdam ellipse is a Standard Deviation Color Matching (SDCM) protocol for describing visibility of human observers of differences of sources, by how far they deviate from a reference color. Each ellipse represents a standard deviation from the reference (center) source. It is generally accepted that within 3 MacAdam ellipses, most observers cannot discern a difference between two sources. At 4 steps, a significant sampling of observers would see a color difference. At 7, virtually everyone will see a difference. For a more complete background, there are numerous sources describing these details, such as https://en.wikipedia.org/wiki/MacAdam_ellipse. The shape of the ellipses varies by color, as human visual differentiation changes in both spectral sensitivity as well as range between sources.

With this, it would seem pretty straightforward that when someone claims their product, LED, or light sources fall within 2 or 3 steps, that it can be assumed that the difference between two sources from that provider will be unseen. Unfortunately, a common miss-interpretation and incorrect application of the MacAdam ellipse protocol creates an actual deviation that can be as much as double that stated. The illustration below shows how this happens. (more…)

The Adventure with Architectural SSL Magazine

In 2006, I pitched the idea of a magazine dedicated to Solid-State lighting technology as it applies directly to architecture with the owners of Construction Business Media. After a few pizza lunches and more convincing, they moved to creation of Architectural SSL magazine in time for Lightfair 2007 with its debut issue.

Since that debut 12 years ago, I have participated in editorial discussion and planning, contributed content to every issue with a market setting feature, a closing remarks Op Ed, white papers, judeged products, provided reviews of various products and provided general commentary on the progress of SSL into the lighting market. (more…)