Finally 300 Lumen Per Watt !!

[TorchBoy]

There's a big difference between candlelight and direct sunlight at the equator, even though both are "full spectrum". For continuous-spectrum sources, more lm/w can be achieved in a lower color temp (green and even red light are better detected by our eyes than blue).

I'd accept more easily focussed. For our peripheral vision in particular, blue light is detected (not "more easily"). And there's a big difference between full spectrum and continuous spectrum.

Generally, there is a trend where the lower the illuminance is, the lower the ideal color temperature is. So comparing a candlelight to the typical illuminance of even a modern incan-lit house, let alone a store or office, isn't a fair comparison.

I guess you're thinking incan lights, because that's what we've mostly had, so you should really say "normally produced" instead of "ideal". Our night vision is most sensitive to cyan light, so the less light there is the higher the ideal colour temperature is.

You know candles are not always used just for illumination, right? Perhaps I was confusing things by even mentioning them. Sorry. There'll always be niche uses where efficiency doesn't matter. Lets forget candles.

 

[saabluster]

I don't think that really addresses the possible problem of too much blue light when we're trying to go to sleep, but quite apart from that, we simply may not want white light in the evenings. If someone came up with a new kind of candle that burned with a pure white light how romantic would they be?

I have felt this same way for many years. That the bluish tint LEDs would never make good "mood" lighting. However, I was at Ikea a few weeks back and they had a chandelier made of LEDs inside of white opaque balls. They had a bluish tint to them. I was struck by how "romantic" they were. It seemed to mimic moon light. What could be more romantic than that?

 

[FloggedSynapse]

From the article:

The crystals absorb some of the LED's blue output and emit their own red and green light. That combines with the remaining blue light to produce a soft white glow.


Existing commercial white LEDs are also based on blue LEDs. But they use a phosphor coating that converts some blue light into a broad spectrum of yellow light. When mixed with remaining blue light the result is a harsh blue-hued white.


Nanocrystals emit light in a much tighter range of wavelengths than phosphor, making it possible to fine-tune the colour produced, Demir says. "Using combinations of nanocrystals, one can generate any emission spectrum as desired," he told

Interesting.. essentially it's an efficient RGB light. I'd like to see the spectral plot.

This is not new. Check out this article from over 2 years ago now:
http://www.vanderbilt.edu/news/releases?id=22603

These people, using nano-crystals, were able to create a pleasing white light from a blue LED - true "continuous spectrum".

The nano stuff is interesting, as researchers are now finding many interesting effects that can be created when structures much smaller than the wavelength of visible light interact with it.

This is good news for LEDs - more efficient, and hopefully a more pleasing light. The current crop of LEDs are good, but the quality of the light has a ways to go before more people will start using them.

 

[jtr1962]

I have felt this same way for many years. That the bluish tint LEDs would never make good "mood" lighting. However, I was at Ikea a few weeks back and they had a chandelier made of LEDs inside of white opaque balls. They had a bluish tint to them. I was struck by how "romantic" they were. It seemed to mimic moon light. What could be more romantic than that?

My thoughts exactly. Low level lighting with LEDs mimics moonlight or starlight. To me that's much nicer and more "romantic" than candlelight. Truth is I hate candlelight. It's too dim and way too yellow. Color rendition under candlelight is pretty close to zero. It's not perfect under LED either, but it's way better than under candlelight.

 

[jtr1962]

But the core issue is that daylight should be the reference, not incandescent light. People holding onto the notion that the the ancient light bulb is "right" is a problem that continues to hamper adoption of fluorescent lightning, and which will carry over into the age of LEDs.

And the funny thing is that when incandescents first came out people who were used to candlelight felt they were too harsh, too white. Yet now they are considered "normal" by many people. I think it all comes down to people being used to a certain look in their homes after dark. If you've always used incandescent, then anything else looks weird. I think it also has to do with people not spending as much time outdoors as they used to, and therefore not having a good frame of reference for sunlight. I used to play a lot outside as a kid. As an adult I do gardening, walk, and cycle. Even though I mostly cycle at night, I still had/have enough exposure to normal daylight that incandescent light looks weird to me. Actually, this was always the case. I preferred the cool white circline fluorescent we had in the kitchen to the incandescents elsewhere. Once I got older, first thing I did in any room I spent time in was to put in a linear fluorescent fixture. Granted, the old T12 cool whites had horrible color rendering compared to what we have now, but I still preferred the more accurate white point. Once I discovered 5000K high CRI lamps, it was really all I could wish for. I tend to think the younger generation, those who are children now, will not have the preference for incandescent-like lighting that their parents do since they've been exposed to white LEDs in many products. To them white light will mean sunlight white. I predict that although 3000K and 3500K LEDs may be king for a while in interior lighting, within a generation 5000K catches on big time.

I also tend to agree with 2xTrinity about having linear tubes in non-utility areas. I don't get why so many people think it's weird to have a linear tube fixture in a bedroom or family room. They can be integrated into the decor much more easily than a bulky, dust-collecting chandelier. If more people used linear fixtures, we might actually have fairly inexpensive dimming ballasts. Besides the advantages of superior light distribution, T5 or T8 tubes can last as anywhere from 3 to 5 times as long as CFLs. They also seem more reliable. There are a lot of CFL failures long before the expected end of life. Not so for linear tubes which usually last their rated number of hours.

 

[TorchBoy]

Color rendition under candlelight is pretty close to zero.

I thought candlelight had a CRI of 100.

I think people haven't liked fluoro tubes for bedrooms because for years they had quite a harsh light. Times change.

 

[laur]

Boy, I can't believe the response my post has garnered!! Reading through the replies you can see the depth and breath of our membership. CPF is the place to be for the latest information about lighting, knowledgeable technical help, friendly conversation and a forum for fellow "flashaholics". Thanks to Sasha for making it a reality

There is so much good info in this post, I think we should make it a "sticky".

Thanks to everyone who has posted. I have learned a tremendous amount about LED's and nanotechnology from reading the replies.

laur

 

[liquidsix]

This reminds me of an article a year and a half ago about improving led efficiency by cutting patterns into it to increase surface area. Some of us speculated it would be years before we saw the result of that. Then the Cree XR-E 7090 came out soon after, and unless I'm mistaken, it's manufactured using this technique. So maybe it won't be too long before we see this improvement too. I know that this crystal coating is probably more complex than cutting patterns in a dye, but all I'm saying is we may see it sooner than we think.

 

[jtr1962]

I thought candlelight had a CRI of 100.

Any blackbody technically has a CRI of 100. A heating element glowing a dull cherry red has a CRI of 100, but wouldn't allow you to see too many colors. A candle's spectrum is extremely weak in short wavelengths. Therefore, rendition of blues, violets, even greens is poor. Really, the only colors I see under candlelight are reds, oranges, and yellows. It's the combination of CRI and CCT that makes a good quality of light. CRIs much less than about 80, and CCTs over about 7000K, or under about 4000K, cause pretty severe color distortions. Candlelight is around 1700K.

I think people haven't liked fluoro tubes for bedrooms because for years they had quite a harsh light. Times change.

Note the operative word "had". Unfortunately, fluoro tubes still get a bad rap due to the shortcomings they had years ago. I still hear people tell me how they hate the flicker of fluorescent even though all CFLs, and most linear fixtures, use electronic ballasts with no flicker. And by association any white light which looks like fluorescent is automatically considered "bad" before it's even given half a chance.

 

[Calina]

This is VERY cool. Thank you for posting this. However it should be in the LED forum.

It is already discussed in the LED forum, but you are right, this thread belongs to the LED forum. The two threads should be merged.

 

[TheCowboy]

Well when you guys want to get serious about making a real torch, let me know because we just came out with our ZP20 20 what LED.
Any questions, contact me at the email address below.
Here is one of our earlier postings:
If you write to us, be patient for the reply as we are now selling our LED outside of the US as well, and not just in the US anymore.
Serious inquiries only.

Hello Guys,
First of all, the P7 is not the brightest LED bulb, although Surefire would have you believe it.
Our ZP20 20watt is perhaps the most powerful LED produced today.
We do sell it to companies other than Surefire, so interested parties may contact us..
We also sell the ZP10 10watt led comperable to the p7 10 watt.
We prefer not to export these outside of the US in small quantities, but
People interested in purchasing the light may contact me directly at my personal email. We will sell in quantities as low as 10.
I will send pictures, pricing, etc... These are not toys, so Please, only serious purchasers ready to buy need contact me as we have lotsof business as is.
The Cowboy

my contact email for the ZP10 and ZP20 is [email protected] I prefer this email as I will not give out our website email except to real buyers of our led products.
PS, we sell in quantities from 10 to 50,000.
Free shipping is standard
The CowBoy

 

[fletch31]

Hey Cowboy, do you have a link to specs for these LEDs?
Maybe we should get something going for a group buy.

 

[tobjectpascal]

One thing to consider with this LED is they didn't mention the actual max wattage. It might get 300 lm/w , but what if this is only when being driven at 25 mA ???

Yeah fair enough but what if you could only drive it at say 300ma which is reasonable, 300ma outputting 200 lumens which will run for 8 hours is by far better than a 200 lumens flashlight running for 2 hours at 1amp... (no i can't be bothered to calculate it .... i was estimating)

 

[TorchBoy]

we just came out with our ZP20 20 what LED.

Ok, I'll ask. 20 what?

Our ZP20 20watt is perhaps the most powerful LED produced today.

Perhaps... not (DX even lists some specs ). And I guess you missed the thread (in this post) where the 500 watt LED was mentioned as an aside to the thread topic, which I guess was something much more exciting. :thinking:

I had a look at www.shoppinhaven.com. I hope it's not your site. It's pathetic. The home page is waaaay too big, there's no search feature that I could see anywhere, and the Electronics page didn't exist so after the auto redirect after 10 seconds I ended up at Homestead's home page.

BTW, :welcome:

 

[RustyKnee]

Ok, I'll ask. 20 what?

I nearly posted that and resisted hehe. love your sig line.....so true

TheCowboy, Watts used alone for LEDs isn't particularly helpful....especially ina thread that is talking about efficacy. Any other figures?

Stu

 

[TorchBoy]

Momentary diversion from the thread...

I was passing through LA international airport a few years back and in my hand luggage I had a single 5mm LED torch, homemade in a 3xAA switched battery box. A security guy was having a close look at it and asked what it was. Being rectangular in shape, it didn't look like anything he had seen before. Of course, I said "A torch."



He said "A torch?" and looked me right in the eye. He had looked a little bored, but I certainly got his attention with that.

I blurted back "Flashlight! It's a flashlight!" and managed to persuade him it could be turned on.

 

[Mockingbird]

"

. Much like a certain flashlight (with 4 leds) I ordered a year ago and haven't received yet, but that's another story..."


Monkeyboy,
When you do receive it, keep it in your vehicle in case you need to smash a window to escape a watery death. It's HEAVY!!!

 

[tobjectpascal]

While working in security you soon pick up things that once known could easily have you fool them, you know how to get pretty much anything through, be one of them annoying people the ones who ask too much that will work, security are trained to spot the little things, for example if someone asks you to put your arms out to be searched an innocent people would get angry guilty people don't they will say little to not draw attention to themselves, innocent people do not, do you know how easy it would be to place a ceramic knife at the bottom of your shoe i bet anyone could do it and get away with it, unless you're very quiet and say nothing... ironic really lol

 

[AvidHiker]

I nearly posted that and resisted hehe. love your sig line.....so true

TheCowboy, Watts used alone for LEDs isn't particularly helpful....especially ina thread that is talking about efficacy. Any other figures?

Stu

+1

Who does this "Cowboy" guy think he's talking to? His post absolutely reeks of BS. If you're looking to scam someone or start some buzz about a nonexistant LED for your own amusement, you should have done your homework first... idiot.:ironic:

 

[TorchBoy]

Careful there tobjectpascal, you've probably crossed the line with that one. http://www.candlepowerforums.com/Rules.html#disclaimer

You agree, through your use of this BB, that you will not use this BB to post any material which is knowingly illegal or promotes illegal activity.

I found this definition for cowboy: Someone who is reckless or irresponsible (especially in driving vehicles).

Cowboy, if you want anyone to take you or your LED or your business seriously, cut out the braggadocio and give some solid information, such as the specs, instead of bluster.