What is the wavelength of pure yellow?

[zyxwv99]

561 - chartreuse bannana yellow-green
568 - about the same as above, but more yellowish.
577/578 - lemon yellow
589 - golden yellow (has an orange tint)
593.5/594.1 - amber yellow/yellow orange (a bit more orange still, some people may even see it as orange. especially in the dark)
604 - orange, with a hint of yellow.
607 - orange
611.9 - red orange
632.9 - pinkish red with some orange in it

I've ran these wavelengths by eye in the downtown lab, and this is what is commonly agreed upon.

Thanks. That's about what I was thinking on these wavelengths, although I'm not sure sure what "lemon yellow" means. Is there any detectible green in that?

 

[BurningLaserGuy]

Thanks. That's about what I was thinking on these wavelengths, although I'm not sure sure what "lemon yellow" means. Is there any detectible green in that?

I don't think so... I mean only if the lemon is actually lime.:beer:

 

[Teej]

I don't think so... I mean only if the lemon is actually lime.:beer:

What if its a Limon?

 

[ultimatekaiser]

Thanks. That's about what I was thinking on these wavelengths, although I'm not sure sure what "lemon yellow" means. Is there any detectible green in that?

its literally solid yellow. no detectable anything in it. its a bright true yellow. as it approches 570 it gets hints of green. as it gains toward 580 it gets more orange.

if you compare the beams (not the dots, all of them look similar) the beam of 577 is quite an intense yellow, where as 589 and 594 have successively more orange in them. 589 has just a bit, but its there. but its not really visible in the dot due to the intensity. 594 it starts to show on the wall, but not much. but the beam, or diffusing it into something is clearly orange.

red is kinda the same way. 650+ all just looks 'red' on the wall. but by reducing the intensity somehow, makes it get successively darker and more dark ruby colored as you move toward 700. 680-690 is like 405 and harder to see. but all of them side by side on the wall are fairly hard to differentiate between

 

[trencheel303]

I see the beam of the 593.5 to be golden. The dot is more or less orange but the beam I can only describe as golden. It's kind of strange.

 

[ultimatekaiser]

I do too with fog, but it still has a light orange tint. but i'm talking a beam at 100+mW that's low intensity and natural from scattering on the air, rather than fog or other particulates. the intensity makes it look more and more yellow. my 594 is technically more orange, but looks more yellow to me because it is 4x as powerful as my 593.5nm pointer. but diffused through as spacial filter or into my lamp, they look orange. 589 on the other hand actually appears a bright golden yellow, with a hint of orange.

This picture shows it pretty well:

 

[Atomicrox]

Regarding previous posts, the English word "orange" certainly violates their own rule, as the examples given are gold and silver (on what to avoid in doubtful cases). However, none of the languages surveyed were English, so I don't think that's a valid criticism.

Next, lots of researchers have looked at Berlin and Kay's work. There is a whole body of published literature examining the methods used. The World Color Survey has gone beyond the work of 1969. However, the Munsell color chips make sense when you consider the issue of continuity. For example, the famous MMPI test (525 questions) used in psychology was developed in the 1930s. Some of the questions have words that people today can barely understand, such as referring to women as "broads" and "dames" or alcoholic beverages as "hooch." (Or something like that.)

Next, on the LED issue. The advertized wavelength of an LED is just the intent of the manufacturer. If you want to know the real wavelength, it needs to be binned. They test them with a digital spectrometer, then put all the ones that fall within a certain wavelength range in bin number 1, the next wavelength range in bin number 2, and so forth. Except the bins actually have 5-digit serial numbers. I think traffic-light diodes are binned.

Then there's the dominant wavelength v. peak wavelength. The latest generation of Don't Walk signs have peak wavelengths of 620, but dominant wavelengths of 610. To figure out the dominant wavelength, get a spectrometer reading, then divide it into 1 nm slices. Adjust each slice for CIE 1931 (which is how they do it) or CIE 1978 (which is how I would do it). The resulting curve will have a lower peak. However, what we really need is the center of gravity of this new curve, since it will no longer be symmetrical. Divide this new curve into an odd number of equal-area slices (in terms of area under the curve) then pick the middle slice, even if it's not the highest one.

Sometimes they tell you what the dominant wavelength is.

As for 611 sounding unbelievable, I too am having a hard time wrapping my brain around that one. Maybe we need to go out and find some new-generation Don't Walk signs. Oh wait, is 611 the dominant wavelength or the peak wavelength? I'm confused.

This diagram uses CIE 1976, which is "dominant wavelength."

http://library.creativecow.net/arti...amColor_CRT_Replacement/DreamColor_gamuts.jpg

scroll down a bit: (no idea of what CIE version they used here)

EPSON Perfection 4870 PHOTO Scanner Review: There Is No Limit to Perfection!. Page 17 - X-bit labs

Some of my LEDs specify the WL as dominant, others don't specify. I don't think I ever bought one that specified the peak WL.

I'd do some color matching tests shining low power LEDs and lasers on the monitor but I've had an eye surgery and the last thing I should do is stare at bright lights, so it'll have to wait.

Maybe one of the guys with spectrometers could help us by measuring LED's and other light sources and comparing them to their monitors?

Edit: actually the best option is to meter the monitor primary colors. Fill the screen with red, green or blue and take the profile. ARG probably wouldn't mind doing this.

its literally solid yellow. no detectable anything in it. its a bright true yellow. as it approches 570 it gets hints of green. as it gains toward 580 it gets more orange.

if you compare the beams (not the dots, all of them look similar) the beam of 577 is quite an intense yellow, where as 589 and 594 have successively more orange in them. 589 has just a bit, but its there. but its not really visible in the dot due to the intensity. 594 it starts to show on the wall, but not much. but the beam, or diffusing it into something is clearly orange.

red is kinda the same way. 650+ all just looks 'red' on the wall. but by reducing the intensity somehow, makes it get successively darker and more dark ruby colored as you move toward 700. 680-690 is like 405 and harder to see. but all of them side by side on the wall are fairly hard to differentiate between

I do agree it's easier to see color differences on unfocused dots. I see 685nm just fine but 30mW looks (brightness-wise) similar to about 3mW of 650nm. No crazy unfocused colors or anything, unlike 405nm.
Best way to see the difference on reds is to shine them on a diffuse matte surface, like some kinds of slightly translucent white marble. There I can see a very slight orange tint on 635nm, 650nm as "pure red" and 685nm as slightly "crimson". 780nm and 808nm look more like 650nm to me, but it's hard to compare because of the brightness difference.

 

[ultimatekaiser]

that was what I was referring to. after about ~660nm it starts to look pretty much the same, just more and more lackluster/intense as you move toward IR. it gets perhaps a bit darker and purer red...but its very difficult to tell. 660-670 is more true to deep red to me. 650 still has a touch of orange in my opinion. I'd describe 660-670 a kind of 'cherry red'

 

[Atomicrox]

TBH I meant anything around 650/660nm, as I don't have the tools to differentiate, nor a 670nm laser. But yeah, it's *way* harder to tell a ~35nm difference there than a 10nm difference around 450nm.