The Holy Grail emitter or fools gold?

I like standards. It gives me a point of reference. Like measuring the size of a flashlight with something you are familiar with. In photography one uses a gray card as a point of reference. Printers use the Pantone Matching System. PC Computers use Bill Gates as a point of reference. /ubbthreads/images/graemlins/grin.gif

Using a standard helps me when I want to deviate from the standard and tells me how far I have deviated.

Is there a standard for a Lux LED emitter? I would like to find the ideal light-tint emitter so I can use it for a reference to see the difference between emitters. Is there a "Holy Grail" emitter tint that matches the tint of the Sun?

Yesterday the man from MARS came to do a job at work. Really! He is the Mobile Auto Restoration System man. The man from MARS. He saw me playing with one of my MicroMag lights. He told me he uses a neat light that is 99% accurate to sunlight and within 30 seconds we had the web page SOLUX on the computer. Dennis, the Man from MARS, told me he uses the light to match his airbrush color repairs on cloudy days so when the sun finally comes out the color will remain a match. Dennis is good; he knows his stuff. Dennis then asks, "Would you like to see my light? I have it in the trailer of my truck."

And how I would! In the truck he pulls out a box that looks a lot like a movie klieg light with a small reflector and bulb in it. He plugs it in then switches the Solux on. We are bathed in a happy warm yellow beam that is very pleasant. It is like sunlight in the trailer.

My ulterior motive was to color match my favorite emitter color tint to see how far I was off the norm my favorite light was. I wanted a standard that I could match tints with other lights. What surprised us both was when I turned on the MicroMag light. The two lights were an exact match...EXACTLY THE SAME.

When I describe the emitter tint I like I use the word sunshine. My emitter tint of my choice is the Lux 3 TV1 series. The MicroMag we were comparing has the TV1 series emitter.

We tested the TV1 emitter and the Solux light against lots of color charts and the TV1 emitter matched. Dennis told me metallic paints were the toughest colors to match but the TV1 emitter and the Solux still matched. We moved the beam of the two lights together and separated them and the two beams seamlessly merged together. Unfortunately it was cloudy and rainy outside the trailer so we couldn't do a real sunshine test but Dennis assures me that the Solux light does match sunlight. Do you realize how silly it all looks to have two people in a trailer for 10 minutes waving lights around? /ubbthreads/images/graemlins/grin.gif

Dennis was impressed enough with the MicroMag to ask if he could have one like it so he could have a portable Solux light.

Could I have found the "Holy Grail"- a standard of a piece of sunlight to compare other LED emitters to or have I found "fools gold?" Is the TV1 emitter the Holy Grail?

TV1, is that Lux I or III bin?

Tint bins cover a lot of ground. Your TV1 likely isn't going to be the same as the next TV1.

No "cool white" Luxeon that I'm aware of has a CRI as high as Solux claims for their products.

Unless I understood wrong, LEDs do not emit all colors of the spectrum. Hopefully someone with more knowledge will chime in. This is interesting!

It's a Lux 3 emitter.

I do know that there are variations of tint within its category but it would be a start to see variations of different bins of emitters.

[ QUOTE ]
GarageBoy said:
TV1, is that Lux I or III bin?

[/ QUOTE ]
That would be a Lux III.

The best known Lux I bins are R.

The V1 color tint should hit a spec of 5500K, while the Solux shows three available CCTs of 3500, 4100 and 4700K; it would seem that the TV1x Lux III could be close to the 4700K of the Solux light, but the question is how much variation in K is required before the human eye can distinguish a difference?

haveblue,

IMHO, I think you are just lucky with your TV1x.

I have three examples of TYAJ, two TVOJ and one TWOJ that all look fairly *white* when viewed alone, but different by a rather large margin when compared together. The biggest surprise is that some of the larger differences occur within the same bin! My TWOJ and one of the TYAJs and one of the TVOJs are very close, while the other TYAJs exhibit varying degrees of bluish to blue/purple tint. YMMV

Aloha

Brian

White LEDs are blue emitters with a green phosphor coating, so in reality, it's a faux-white. ~They dont emit any light in the red part of the spectrum, so i think your search is in vain (for now).

sure they emit in the red.

Here's the spectrum:



Notice on the top that red centers around 630nm, where the relative red output for the white is around 0.4

Where does the red come from?

The phosphor.

Here's the spectrum for the warm white. Notice that emission is heavy in the red. The difference is in the phosphor mix.

Also, daylight varries greatly. High noon is way different the sunset. The rule of thumb I use is 5000K or 5500K is a good daylight. Higher or lower and you get yellow or blue tints. Also you should compare a spectral graph of daylight to the above graphs. It will give you a better idea of what is going on.

BTW - Daylight on a cloudy day is still considured daylight. See what a big range daylight can be.

To see what colors your Luxeon is emitting, shine it at the back of a CD in a completely dark room. The CD acts like a diffraction grating and the colors you'll see reflected are the spectral output from the Luxeon. I assure you that red IS present, just not much and not very bright either.

It is very interesting to do this with different Luxeon bins to see what the brightest part of the spectrum is.

The point I was trying to get across was that maybe the TV1, or other emitter, could be the beginning of a standard color to judge tint of other emitters. Sure there are variations of emitter tints.

There are variations of sun emissions depending on the time of day; the Solux might have slight variations in tint because of voltage, age of the filter and age of the lamp. Photographic gray cards can have variations of tint and the Pantone Matching system book could have variations in ink printing. But the variations are within acceptable limits.

I'm sure that Solux has done a lot of research before claiming their light emits sunlight. And I know of one sole proprietor touch up car painter that has to match paint colors on cars exactly. He approves the use of the Solux on overcast days to simulate sunlight. On overcast days that Solux is the car painter's godsend. He couldn't paint on overcast days because the cloud cover would absorb some of the visible spectrum of light. Dennis uses the Solux on overcast days because the neutral tint of the lamp matches sunlight. So Dennis has no surprises when the sun finally comes out to reveal his color and tint match remains the same.

Project one step forward if a Lux emitter matches the Solux beam with Dennis' professional eye I would say that that particular emitter could be a standard; it could be a "Golden Grail" emitter to judge other emitter tints.

I won't argue that there are color differences to everything but I think a standard color would be good so we can see variations of colors and how far deviant colors vary.

I'm pretty surprised that your emitter produced enough light in the red wavelengths to match the Solux light. That's my layman's opinion, and it's been hashed over above.

I like the V1 bin personally, but everyone has their preferences. Is CRI the measurement of how well/real a light source renders colors? I see that the Solux bulbs are not expensive. How much would a set of reasonable color samples cost? It might be worthwhile to put together a qualitative test for color rendering based on your experience. Yet another beamshot photo to add /ubbthreads/images/graemlins/smile.gif

I have an interesting photo of a repaired section of a white car. Both my wife and I have physically looked at the repair (and she has great color observing capability) in daylight, overcast, and various indoor lights - it is a perfect match as far as we can see.

Guess what - the picture shows it up obvious as ever. Completely different colors. I am sure there is a reason that has to do with the film, but I am not sure what it is.

I do have 10 of these TV1 series emitters so as I get them online in the next few days I'll have to see how much of a variation there is between them using my personal standard TV1 emitter.

I should see Dennis, the painter, in the next few days so I'll see if I can get a beam shot of the Solux and the TV1 emitter next to each other. Of course I can already guess that the camera white balance is going to mess up the photo since the spectrum of the two light are radically different.

Flatscan...I also like the TV1 emitter. It is a pocketful of sunshine. There I go using that sunshine word again.

HarryN,

Did you use a flash for the picture? If so, that may be why you could tell the difference in color in the picture, but not with the naked eye. It may be the flash, not the film.

David

In actuality to have a truly *white* light... you must have a fair amount of red emission of light... I take it none of you have seen a tv set when the red gun dies, it looks sickly bluish green and whites are not white any more. It is one thing to have a *tinted* LED output, another to have a colored output like a green, blue, or red LED.