Friday, November 15, 2013

Looking For A Reading Light

A story here is first told in a web album:
Looking For A Reading Light 

Now tell the story again, here.

I have a genuine need for a bedside reading light. But for the living room with its fancy ceiling, each room is lit with one or more Glimpse LEDs, mounted in new RACO175 junction boxes of course. An overhead light is crummy for seeking sleep, badly aimed at a book, and not amenable to drowsy shutoff.

As a solution, I was offered this desk lamp with ready-to-go 100 watt incandescent bulb. I just can't bear to use it. I tried a clumsy directional LED bulb appearing in photos to follow. No go. I couldn't keep the lamp from toppling. 

I no longer expect to find innovation at Home Depot, but dutifully walked the aisles again this week. I found this, and went on to also buy new T47 and T67 disk lights. I hoped the bad dimmer buzz in those disk lights might be resolved. Wishful thinking, and all three trials will be returned. Darn the packaging. With this ecosmart, know to twist out the front-face bubble with little damage. Never get angry and use a knife or scissors.

I would try this much-lighter new version of the ecosmart technology, in my lamp!

Here is a labeled array of bulbs discussed here, out of packaging.

The year-old "75w" version of the ecosmart LED is at left. Next to it is the new "65w" ecosmart. At right is a Utilitech version of the L-Prize replacement of a 60-watt incandescent. 

Labels A through D are edited-in, for comments to follow. First, note weight of each. A = 429.2 g. B = 145.2 g. C = 27.5 g. D = 247.3 g.

In the desk lamp, the "65w" ecosmart is still toppling, and a bit ugly. I won't use it.

A 65 watt incandescent flood looks the same and is less toppling, but I won't use it even in cold-cold winter, where the heat feels good. I'm leaving that in place for night-time fumbling-for-a phone. It beats any stupid point source bulb. It's hard to believe people still use "bulbs."

Here is a collage of three individual photos of task illumination, with very limited discrimination of brightness. I use a Canon Digital Rebel SLR camera in No Flash mode for all comparisons. The setting allows automatic adjustment to found light, and individual photos are not comparable, except perhaps that brightness might be reveled in better camera focus achieved. It is not the way to do testing.

Again, I can rely on my Living Room test stand for unambiguous comparisons. Comparisons are most valid where side-by-side specimens have the same color temperature.

At left is a 4" Glimpse, 2700°K, 425 lumens.

At right is the "65w" ecosmart, 2700°K, 650 lumens.

Labels applied to comparison photos state unambiguous conclusions, where Brightness Numbers are noted. B4 is the standard, assigned to a 100 watt incandescent bulb. For all directional light beaming from a plate, compute Brightness Number as:
Tested Lumens/450 * B4.

The topply Ecosmart LED flood in a reading lamp is brighter than a 100 watt incandescent by *650/450 , brighter by  44%.

Here is one more demonstration of "B4", equivalence of a 100 watt incandescent and a 3000°K 4" Glimpse, 450 lumens.

Add some more test-stand observations. These will further illustrate that task illumination, that properly distinguishes luminaires of differing construction, is not at all expressed in numbers of lumens or lumens per watt. The observations are useful in seeking a reading light, applying Year-2013 source material for a Year-2016 debate about "High-Efficacy Lamps." This addresses misconceptions about point-source LEDs. The point to be made is that a point-source lamp of any kind can never be "high-efficacy." An LED bulb that might screw into an old reading lamp must be directional with large beam angle, not with some concentrating lens. See the inefficiency of the US DOE "L-Prize" point-source LED bulb. vs. good directional LEDs:

A point-source LED A19 bulb, the Utilitech offering of the L-Prize bulb, gives really-awful illumination. Such expensive bulbs should never be used as desk-lamp reading light. Point-source bulbs are inferior for any task illumination.

It really hurts consumer decision-making when directional LED lighting is under-rated, by a large amount. It is time we fixed the packaging.

I'm still waiting for a good reading light. It might be in an art piece suspended from the ceiling. For a child, I have imagined illumination from "landing lights" on a remote-control model airplane, at quite modest cost. For me, it might be a soft-light broad panel with some provision for aiming, mounted to the wall. All best solutions will come where we at last have direct attachment to low-voltage DC.

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