Are you interested in LED light?

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I would like to know your opinion about led light, do you think it is necessary for us to change our traditional light into LED light for saving more energy and cost.

I think it's both necessary and inevitable. Incandescent bulbs have largely been phased out over here.

I can think of a few reasons why LED is the future of lighting:

LED-bulbs that are designed to be a replacement for incandescents are now becoming more efficient than their predecessor, the CFL. E.g. a 11 W/600 lm CFL (51 lm/W) can be replaced by a 9.5 W/600 lm (63 lm/W) LED-bulb of the same colour rendering and colour temperature.
Of course, total running cost is still higher for a LED bulb, so prices will need to come down some more first.

LEDs do not suffer like CFLs from repeated switching. Each ignition of a CFL seriously shortens its life. I've seen CFLs fail in a high cycle application with only a couple of hundred hours on them. I've also seen CFLs exceed their expected lifetime by a factor of 2 to 3 (!) in on-at-dusk-off-at-dawn type of lighting. On some, the ballast failed before the lamp, and my guess is that LED bulbs with good heatsinking of the LEDs will show the same failure mode.

LEDs do not need a warm up time to give full light output that is so typical of fluorescent (and other types of gas discharge) lighting.

LEDs do not contain mercury.

LEDs for ligting purposes do not have IR or UV in their light beam (LEDs made specifically for emitting UV light do exist, BTW).

IMHO, made-for-LED luminaires are the future of LED lighting. These can make optimal use of the directional spread pattern of LEDs increasing system efficiency (light source + luminaire effeciency).
A high efficacy model for office space ligting was recently introduced by the company that was founded in my hometown. The existing model was already good for 80 lm/W, the HE model does 110 lm/W.

The same company is also making LED lighting sources that gradually change their CCT from 2700 K to 2200 K when being dimmed to create the same effect as dimming an incandescent bulb.

When street lights are at end of life in my city, they are being replaced by LED luminaires. To my surprise the glare from these luminaires is less uncomfortable than I expected (better than HID).

In my own home, I use a mix of (halogen) incandescent, (C)FL and LED, depending on the application.

BTW:
2700 K = warm white light, like incandescent;
3000 K = warm white light, like halogen incandescent;
4000 K = cool white light, standard workspace FL lighting;
6500 K = daylight white, however appears as blueish to the human eye when viewed in low intensity.
 
I have very few (<5%) incandescent of the "old" variety.
I have a lot (~50%) of the halogen type incandescent.
I have a few (~10%) of the long tube fluorescent.
I have a lot (~25%) of the CFL replacement type.
I have a few (~10%) of the LED replacement type.
I have no dedicated/exclusive LED type.

All the "new" have a longer life than the "old"
All the "new" have a higher light to electric efficiency
All the "new" except long tube F have less light than the claimed equivalent incandescent.

It seems much of the bad press and bad reputation for the "new" is down to excessive claims by the proponents.

If we do our research the truth is out there.

I expect light output increase ref same input to be: halogen + 20%, CFL to be +200%, LED to be +400%, Long tube to be +300%, from my experience in domestic use.
I prefer LED replacement to CFL replacement for colour rendition. and halogen for best colour rendition.

BTW,
as with many other stats posted in this Thread which are clearly wrong, white light is not 3000K. Ask any traditional (colour) photographer for the correct answer.
 
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Doing a bit of WEB research, it looks like vacuum was given up on in about 1913.
For lager lamps, yes. Only the very small ones use vacuum these days. Most common household lamps are filled with argon gas, and a bit of nitrogen. I suppose it helps cool the fulfillment, but don't know for sure. Dry air would be no good, as it contains oxygen.


As for 3000 degrees K for white, it's "warm white" in common parlance. 3200K is typical white for hot lights, 5000K or 5500K for daylight balanced lights and flash. Video white point is usually said to be 6500K.

(I'm the son of a lighting designer, now in the video biz, so keep all this trivia in my head). :p
 
"Dry air would be no good, as it contains oxygen. "

EXACTLY, which is why 40W bulbs burn out so fast, as do discount ones.

The trick with the inert gas is it helps to re-deposit the out-gassed tungsten back on the filament, not the envelope. They call them "halogen" bulbs.

I am only going by the GE manual. I had a lot of time to kill while babysitting a PDP-8 doing all my work for me.
 
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That's certainly not my understanding. If the bulb had air in it, the filament would burn up in a jiffy. Vacuum is preferred for small envelopes. In typical 40W-200W household bulbs, Argon is used as the inert gas. Halogen lamps are another class, as they have added halogen gas for the halogen cycle. The re-deposit of the tungsten on the filament allows a higher temp filament which would otherwise have a very sort life. FWIW, you can now get halogen lamps inside the typical 60W-100W pear shaped bulb. Those are legal under the new energy rules.

But I'm an end users, not a manufacturer, so my be a bit dim in my knowledge. :(
 
It seems much of the bad press and bad reputation for the "new" is down to excessive claims by the proponents.

If we do our research the truth is out there.

And that is exactly why in the EU it is mandatory nowadays that packages clearly show some relevant data, such as lumen output, average lifetime, warm up time to 60% light output, etc. In the attachment there are two different CFLs, but the same data is to be found on (halogen) incandescent and LED bulbs as well.

The misuse of equivelent incandescent wattage is what probably led to this info becoming mandatory. As you can see it is still allowed, but must be printed in a smaller size than the actual lumen output, and must not be rounded up. In the past a 600 lm CFL was said to be equivalent to a 60 W bulb by the manufacturers, but frosted 60 W incandescents actually did slightly over 700 lm.
I was given a LED bulb a couple of years ago that claimed to be a replacement for "up to 60 W" bulbs. With only 300 lm output, that clearly wasn't true.

Luckily this no longer happens as a result of these regulations.
 

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Luckily this no longer happens as a result of these regulations.

Oh man, those Tornado models put out a lot of light though, i've got 3x of the 18 watt variants, and boy does it light up the shed!

Especially when using a plastic reflector, which should last forever too.

its pretty harsh though the light, which is why sometimes during offpeak hour I turn on the 3x 100 watt halogen lamps, which I did have running off a dimmer but then I thought to myself, hey if this bulb isn't getting hot enough doesn't that mean that the halogen recouperation process won't work, so I ended up not using the dimmer anymore.

Halogen to me gives off the nicest light, if its properly UV shielded, otherwise it dries out my skin then. But Halogen can't be dimmed either I thought.

So its back to the good old 60w-100w incandescent globes for me.
 
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Yes, and recorded music is very bad for the ears. You can go deaf from listening to MP3s, even at low volume. Most of the young people I know are deaf already, if the stuff they listen to is anything to judge by.

Thats actually quite true, the MP3 codec leaves quite a few high frequency artifacts around ready and waiting to pop/damage our kids ears.

Dunno why OGG wasn't more popular, love that codec for when compression is required, like for example audio streaming, it leaves far more of the original signal intact compared to MP3 which rips everything apart.

Especially when in VBR.

PWM to me is just like that, I can't stand it, it might be faster than I can see but I can still feel the damn thing pulsing away at my eye's nerve endings, which nobody seems to care about.

If PWM is going to be the future for dimming LED's and such I'm going to have to stockpile more incandescent globes, leave me out of it!!!!
 
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To me this all points out that different lighting technologies excel in different uses.
I remember reading long ago about the lamps for broadcast antennae, but I probably couldn't recall it until I started climbing.:)
I was reading up on incandescent lamp construction (and destruction) after seeing some posts here. I don't think I've ever heard this before (!):
Study of the problem of bulb blackening led to the discovery of the Edison effect, thermionic emission and invention of the vacuum tube.
 
PWM to me is just like that, I can't stand it, it might be faster than I can see but I can still feel the damn thing pulsing away at my eye's nerve endings, which nobody seems to care about.

If PWM is going to be the future for dimming LED's and such I'm going to have to stockpile more incandescent globes, leave me out of it!!!!

+1

I choose not to dim, but to increase or decrease number of light sources, with LED you can still sprinkle them evenly around the room and have just 1/2 or 1/3 of them on, just use several power supplies to alternating chains of LED on a double or triple switch.
 
................ that packages clearly show some relevant data, such as lumen output, .........................The misuse of equivelent incandescent wattage
your example shows an equivalence of 5times the light for both sizes of bulbs (8W to 40W & 12W to 60W) My older and probably cheaper end of the market showed much worse than 5times
CFL to be +200%,
Maybe I should buy a couple of good quality current production CFLs and compare to incandescent to see if +400% (5times) really does happen in practice.
But instead I have a grant to buy any energy saving device and I'm going to invest in LED replacement bulbs to gain experience in what is available and how they perform in domestic situation. The 10off LED replacement bulbs, I have at present, all do a good job: background room light in table lamps, reading lamp by my bed, 5bulb chandelier for room light. These are 5W 240Vac and state 25W equivalence, 270lumens.
 
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..................As for 3000 degrees K for white, it's "warm white" in common parlance. 3200K is typical white for hot lights, 5000K or 5500K for daylight balanced lights and flash. Video white point is usually said to be 6500K.

(I'm the son of a lighting designer, now in the video biz, .........
I count all the artificial lighting based on incandescent to be "orange" light, not white.
I think of "white" light as outdoor "daylight". It can be anywhere from 5000k to 10000k depending on how much blue sky there is.
But your "qualified" definitions are correct, they just happen to be different from my "daylight = white" definition.
 
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Agree. Real white is daylight, that's what our eyes are made for. But in pro use, film and digital sensors can be designed for a 3200K white point. So in practical use it's "white". And at 3200K, most of us will quickly adapt to it and call it white, tho it really isn't.

Halogen can be dimmed, no problem. It's a filament light, just like any other. Theaters have been dimming halogen for decades. They took over from tungsten theater lighting in 1970s.
 
I'm ham radio, and I have a low voltage line in every room in house and I'm using 220V standard electromagnetic ballast 105W fluorescent tubes, and when power line fails (all the time here in Argentina), I use solar cells to charge a 160Ah battery and low power 11W Osram 12V lights. I love fluorescent light.
 

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Agree. Real white is daylight, that's what our eyes are made for. But in pro use, film and digital sensors can be designed for a 3200K white point. So in practical use it's "white". And at 3200K, most of us will quickly adapt to it and call it white, tho it really isn't.

Halogen can be dimmed, no problem. It's a filament light, just like any other. Theaters have been dimming halogen for decades. They took over from tungsten theater lighting in 1970s.

Hehe, it gets more complicated, just like anything else. In past you could buy film balanced for 3200 K or for 3400 K, where the first one was for nitrophoto lights (Edison screw type white bulbs) and the later if tungsten light is used. Than scientific expression of the daylight is 5500K, specifying summer day at 2PM measured. Prepress or print standard is 5000 K. 6500 K really did not exist as a standard, but with age of computers started being introduced, simply because many monitors could not display lower color temperatures without dimming - lowering its output. If you remember some cheap CRTs when calibrated to 5000 K looked awful. Barco was really the only one that performed perfect when calibrated to 5K standard.

Now, simply color temperature measurement in Kelvin expresses relationship between blue and red. For digital photography or video any of that is completely irrelevant under the condition that all light sources used are same - balanced between each other. In another word, if all lights are 2000K or 9000K it doesn't matter much because once gray or white balance is performed under that light, it all becomes right, just like if we are using 5000K light. Obviously problem comes if we start mixing light sources, like daylight or other lights that are not the same temperature.

The bigger problem often overlooked is relationship between Green and Magenta colors dominant with fluorescent lighting sources. That is why FLs could have higher temperatures, like 4000 to 5000 K but very skewed toward green or magenta. Actually, FLs have a bigger problem - they do not have evenly distributed emission, but spikes in certain regions, particularly in green. Even when they are "daylight balanced" they still do not have a full even spectrum.

As for the color of light people consider warm light much more pleasant, and suitable for afternoon / evening, since that is the time when natural lighting is warm. Cool lighting is considered appropriate for work environment and lighting mixed with daylight. That is why fluorescent lighting that is on the cool side looks so awful and out of place in some homes, seen at night.

The bigger problem in my mind that LED lighting needs to overcome is its character. We rarely use direct light. Home lighting is always diffused or indirect. That is why we use shades, not just to eliminate direct glare, but to soften it and make it more pleasant. Diffused light or indirect light needs more light output to compensate for the loss. Now LEDs have barely enough power to light even directly, so the only solution to that is to use multiple LEDs. But to compete with 75W or 100 W or 150W bulb in a nice big shade, that beautifully illuminates the whole room, we will need many, many LEDs. What I see as a really nice potential is that in order to improve the light quality and light output. one can use three LEDs, red green and blue to create nice white light. For work environment that might be an interesting idea, having a pure nice white light, but without flicker characteristic of FLs

It is very interesting how is hard to win over nice warm globe designed in 1879!

Man. this was long post, sorry.
 
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