Which color LED is most brightness?

Not if you are underwater :->

1 lumen is 1 lumen, regardless of the colour. It all depends on what sensor you are using (human eye or a sensor), and what medium the light pases through.

Dave :)

Hello Boki,

How did you do that test?

Many people's eyes perceive "super red" as the most bright for a given current. But that can be different, depending on your age (no, you don't have to tell us...), degree of color blindness, contaminants such as water vapor (fog) in the path and so on.

--
Regards, Joerg

http://www.analogconsultants.com

Well, how bright is bright? It might be interesting to set up a little jig, with a red and a green (and maybe others) LED, where each one has a pot, with a knob. You tell your victims^H^H^H^H^H^H^Htest subjects to adjust them until they're "equally bright", then take a photometer of some kind, and your trusty DVM, and log what the currents and PHM readings are.

Write that up properly, and you could probably get federal funding. ;-)

Cheers! Rich

Hello Rich,

Supposedly that is the method used in Germany to set the chroma balance when they introduced color TV. At first a dozen candidates or so and when they found that the spread was rather huge they upped that number big time IIRC.

Nah, you'd have to be well connected or know people who are and preferably be in the agriculture business.

--
Regards, Joerg

http://www.analogconsultants.com

David L. Jones =E5=AF=AB=E9=81=93=EF=BC=9A

Of course, my device works on normal condition - between your air and my air ~ In fact, no datasheet, I not sure the LED / due color / tri-color ... will get same lumen ?

Boki.

Joerg =E5=AF=AB=E9=81=93=EF=BC=9A

Um... in fact, test by ................. my eyes, not for verfication.

Many years ago( about 1996 ), I remember that a classmates told me that blue LED was investaged by a Japanese, is that true ?

Boki.

Hello Boki,

Hah! That ain't going to work...

IIRC it was Shuji Nakamara at Nichia Chemical.

I almost got fooled into believing it had been invented much earlier. A friend asked me to drive his car (VW Golf?) back to his house since I was living just across the street. This car had LED indicators for everything. It was late and a dark road so when I switched on high beams, surprise, a blue one came on. Later I was told that this "LED" was actually a light bulb that was made to look like a LED.

--
Regards, Joerg

http://www.analogconsultants.com

Also, since this work was successfully undertaken some 80 years ago - the results of which have been subsequently indirectly verified by many of thousands of researchers and has had universal worldwide acceptance as 'the CIE colour matching chart' for over 70 years - obtaining federal funding will be certain.

Yes I remember those back in the 80's style VW's

When I searched for green laser pointers, I saw somewhere that the human eye is most sensitive to green. So maybe an equivalently rated red and green LED will show the green to appear brighter?

Of course, silicon (etc.) sensors will have different sensitivities.

--Scott