Finally, almost, the LED

Well, it seems that the lengthy, complex and frequently misunderstood tale of the LED should inevitably become a topic of discussion in these pages.  I certainly am no expert on LED (light emitting diode) lighting but it seems on the whole that not many people are.  The LED is something of a freak of nature, a type of computer chip that gives off light, unlike an ordinary diode whose job is simply to ensure that electricity passes through it in only one direction.

Prior to the LED we had the incandescent bulb, thanks to Thomas Edison, which gives off light as a result of high temperature in the filament enclosed by the glass bulb. So simple to make, they cost mere pennies and can be tossed out with the garbage when the filament inevitably breaks (after 1 to 2000 hours).  After 100 years, we are supposed to bid farewell to this lamp (as bulbs are called in the lighting business). Too bad as in many ways it is an ideal light source with a good spectrum (unlike the fluorescent lamp) and even unlike the LED whose spectrum tends to be choppy.  The incandescent lamp works like the sun; if you get hot enough, you give off energy in the visible spectrum (get too hot and you give off X-rays).  The problem with the incandescent is that it gives off most of its light energy in the infra-red spectrum which we can feel as heat, but cannot read by.  As long as your house is in negative heat balance (when you are adding heat, as in the winter), then this is inconsequential.  But in the summer it is a waste, and hence, must go.  To be replaced by what?

The incandescent replacement was to be the fluorescent lamp which has been around nearly as long as the incandescent.  This clever device gives off ultra-violet light, also useless as a reading light as the eye cannot perceive it.  Scientist have used that invisible light to excite a phosphor coating inside the glass tube which in turn gives off visible light, but as noted above, the spectrum is choppy, missing some colors at the expense of others and therefore not giving a good color rendering index (CRI), also a fault of the LED.  Still, it is not bad light and has got better over the years.  The size of both the glass tube and the electronics have been substantially reduced so that the new compact fluorescent lamps (CFL) are an easy substitution for the incandescent…as long as you don’t have a problem with mercury, difficulty in dimming and occasional erratic behavior (changing color, early death, strange flickering, dislike of cold and so forth).  Still, the CFL is about 4 times more efficient at producing light from a given wattage than an incandescent lamp.  I use a lot of CFLs as they save money, and I live with the shortcomings as mentioned, which are not all that bad, except perhaps for the mercury. But who knows? Certainly the government in pushing fluorescent lamps has not been too concerned.

And what of the LED? Much has been said in praise of this unique light source and much has been anticipated.  However, it is still early days for the LED and they have yet to hit their stride.  They are frightfully expensive and tend to have piercing arrows of light that fail to illuminate in that nice, round way of the incandescent or even the fluorescent or candle or even kerosene lamps.  We have been spoiled by the sun and want our artificial light to be as much like our neighbor star as possible.  We were spoiled by the incandescent bulb which emulated the sun in a small scale almost exactly.  If it were not for the energy inefficiency of the incandescent we would not be talking about LEDs and other “efficacious” forms of lighting. Perhaps the sun is not efficacious, but I hear no complaints.

But back to the LED.  Much work has been done to make this light source fill space in a generous way, but so far it is not so good.  An analogy might be made to the oxy-acetylene welding torch.  It produces an incredibly hot (5-6000 degree F) flame, and very useful it is too, in its own way.  But no one would consider trying to heat ones home with it.  Heat for your home needs to be ubiquitous, gentle, non-directional, enveloping. The LED light, in analogy, is none of these.  It excels in ways I do not find pleasing, including emitting an intense light from little round holes in the ceiling in much the same way the annoying MR16 bulbs do, giving an unflattering down-light which hurts the eyes, rather like standing outdoors at mid day in the tropics.

Another annoying aspect of the LED is the use of propriety mounting systems. Once you buy into a system, you better hope that these companies will be in existence a few years hence when you need replacement parts.  You will not be able to go to Home Depot and get the bits and pieces needed to fix an ailing system, most likely. This also relates to the LED hype about longevity which doubtless has been exaggerated, along with many other mythical virtues, in order to stimulate sales.

I don’t want to appear too negative on the prospects of the LED.  I suspect many of these problems will be resolved in a few years, but there remains a need to be cautious.  There are probably many millions, if not billions, or Edison sockets in the world, all in need of replacement lamps from time to time.  This is a market the LEDs should concentrate on.  The Edison base is a standard and should not be tossed away in the eagerness to inflict LEDs on the world. Most of the current crop of Edison base LEDs are mediocre at best.  Too little light, too directional and too hot! While LED’s themselves produce little heat, the power supplies that run them certainly do.

Philips 12 watt LED Edison base lamp

Thus far I have found one LED Edison base lamp that is worthy of introduction.  This is made by Philips and, unlike most these type of LEDs, produces a somewhat spherical light output, approaching that of an incandescent. 


 The curious looking bulb will replace a 60 watt incandescent. The yellow color is misleading as the output is a nice warm white.  This lamp produces 800 lumens for 12 watts of power.  Forget watts as being an indicator of light output.  Now we must think lumens...800 of which will give you pretty much what a 60 watt incandescent lamp used to.
 So I salute Philips for their creativity and understanding of what a lamp should be.  It is intimidatingly expensive, but certainly the price will drop.

Cattleya Lulu

On that note I will introduce another of my orchid friends.  This is a primary hybrid, Cattleya Lulu.  Kind of an unusual name, but what a delight to behold. It is sweetly fragrant as Cattleyas tend. It is important to let the buds open in low light or the magenta spots will bleed all over the white which hurts its appearance, I think.  I have had this orchid at least 10 years and it is a reliable bloomer.

While I claim not be to orchid obsessed (I do admit to it previously) I still find the fascination of these plants irresistible.  Consider the following: Unique in the world of flowering plants, orchids keep their sex organs discreetly hidden. I am not a prude as I enjoy plenty of flowers, especially the lilies, who profligately offer their organs of reproduction (pistil, stamens, anthers) to all the world in hopes of pollination.  Orchids have these same organs, but they are hidden behind veils, accessible only to very specific insects, for the most part, that have allied themselves with each  orchid. While searching for nectar, or simply out of cussed inquisitiveness, they will encounter these organs behind flower parts which conceal them and then, perhaps, pollination will take place. It is a risky plan for reproduction, but the orchid makes up for this by producing a myriad of seeds the size of dust, which it scatters to the winds. The system obviously works.

On the web at Derek Marshall

Who has time for this blogging business?

Ambient, task and other types of light

On to the serious business of lighting.  I make this disclaimer: I am not schooled particularly in what can be a very technical job.  My experience has been empirical, but it does cover a lot of time, close to thirty years, at least.

Lighting can be very subjective and the engineers in this field have made serious attempts to quantify every aspect of lighting which can be a numbing experience with light spread graphs and much talk of lumens and candelas and lux. It is quite hard to get a grip on all of this.  On the other hand, we pretty much all know what the light of a 60 watt incandescent bulb looks like and this makes a handy reference, especially when we get to the “efficacious” forms of lighting, the fluorescent and the LED bulbs.

Back to the topic on hand: Ambient light is the background or “fill” light that illuminates our interiors in a non-directed manner.  It can be harsh and unpleasant as in over-lit fluorescents sometimes found in factories and hospitals or fast food restaurants where too much comfort can result in customers overstaying their welcome. Or ambient light can be soft and romantic as candles on a dining room table with a nice bottle of Bordeaux.  Ambient light is not for reading, applying makeup or creating clever things with your hands. On these occasions we need task lighting.  As the name implies, this is light to help us with creative activities.  However, there is no clear division between ambient and task light as a table lamp can suffice as a reading light if you are sitting right next to it, but becomes a pleasing ambient light to fill a room with a flattering glow. But generally speaking, a task light is usually a small light with a reflector to place light exactly on to your work space and to prevent the light from spilling in every direction.  What is needed is the right blend of ambient and task lighting to get the job done.

The other aspect of lighting is decorative.  While the light may answer to other practical applications, it should also add to the general decorative interior scheme whether it is contemporary minimalism or 17^th century antiquity.  Without lighting you are back in the cave.  What is attractive in decorative light is highly subjective and it would be too self-serving for me to pass judgment on the multitude of lighting available today.

So how do orchids relate to lighting design?  That will take some time to explain, but for now it is interesting to note that orchids, among many unique features, are bi-laterally symmetrical not unlike a human face…or a wall sconce.  More about this anon.   This is a Maxillaria from the mountains of South America.  Strange looking, you may think, and it is.  It is quite diminutive, less than an inch tall and smells strongly of rhubarb.  What more could you want?

www.derekmarshall.com

Starting out...

"Whether I shall turn out to be the hero of my own blog, or whether that station shall be held by anybody else, these pages must show..."

I have been told by those who know more about these things than I that a blog is necessary for a happy life, and is that not what we all are looking for? Baring the soul seems to be a current theme, and if you will forgive that touch of cynicism, then you will deduce that I am not a youth.  How I came to be a designer and maker of decorative interior lighting does not strike me as a matter of general interest, yet I will give a passing nod to that aspect of my work  Better still, perhaps, if you care, you will read my brief bio here -  Derek's CV

My interests are as diverse as anyone's, I suppose, and this photograph is a good indicator.  This plant, in flower for the first time after 10 years of my nurturing, is a South American Phragmipedium, a lady slipper orchid of exquisite and seductive form. Of all the orchids I grow, and there are not as many as there used to be, this is my current favorite. The ten year wait was worth it.

And how does this relate to my lighting designs? Quite indirectly, and yet essentially as well, as I hope to show you.

Well, that's enough for now.  In future I will try to stick more to the main subject of lighting, but interspersed will be some of the things that help define who I am and what I do.  If you care to read all of that, please come back...and by all means let me know what you think.