What is the wavelength of pure violet?

[NightExplorer96]

I voted for 405nm. Have never seen it in real life, but based on the amount of pictures and the "Wavelength to HEX" tool, I would say that looks spot on violet. At least in my eyes

 

[bloompyle]

I agree with the majority here, this is a fairly pointless question.

Also, a lot of 405nm diodes run up to 412-415, but nobody would know without metering it. Also, 445nm diodes run a max negative value of 435, generally no less than 440 though.

So between 405 - 445 is a "no man's land" unless it's been tested, and even still 415 - 435 is untouched.

<400nm isn't even scientifically "violet" it's ultraviolet, removed from the visible spectrum. So that also can't even be counted. That leaves you with only one viable option with those without spectrometers. 405nm.

So that this poll almost pointless. You can't make an educated answer on what you find to be the most "pure" if you haven't even seen it.

Why are these threads being made? You're going to get the same answers in this thread, as was said in the "pure orange" thread. I know personally, if there are 5 or 6 "pure [insert color]" threads, I will lose my mind...

 

[hwang21]

That's because of the little voice in your head saying "want! want! want!" drowning out the voice in your head saying "but my wallet just got over anorexia from the last laser..."

But I agree, there's no "pure" wavelength. Everyone sees the wavelengths slightly differently anyway... half of us can't even focus on a violet laser dot :yabbmad:

 

[Things]

Stick a 445nm laser next to a 488/473nm laser and it looks just as violet as 405.

 

[Encap]

I agree with the majority here, this is a fairly pointless question.
So that this poll almost pointless. You can't make an educated answer on what you find to be the most "pure" if you haven't even seen it.
Why are these threads being made? You're going to get the same answers in this thread, as was said in the "pure orange" thread. I know personally, if there are 5 or 6 "pure [insert color]" threads, I will lose my mind...

Well said bloompyle! Exactly.

To me the question " What is the wavelength of pure violet?" is misleading and not a real question given zyxwz99's expressed vast array of parameters of concern. That question really is asking "which wavelength of violet do you like most" or perhaps "which wavelength do you feel most comfortable calling violet regardless of reason?"

Linguistically, the words/symbols for the visable electromagnetic spectrum of "pure" monochromatic colors have been well establish for a very long time--they are what they are--any wavelength within a given color's wavelength range-- is that pure color--clear and simple--defined for eons already--easy to understand --common knowledge. They are not a mysteries that need discovering and new symbols/words to describe same. All single wavelengths within a colors wavelength range are the pure color not just the monochromatic band peak spectra.

" light in the natural world is almost never purely monochromatic; most natural light sources and reflected light from natural objects comprise spectra that have complex profiles, with varying power over many different frequencies. A naive perspective might be that therefore all these different complex spectra would generate color perceptions completely different from those evoked in the rainbow of pure spectral light. One can perhaps see intuitively that this is not correct: almost all hues in the natural world (purples being the exception) are represented in the pure rainbow spectrum, although they may be darker or less saturated than they appear in the rainbow. How is it that all the complex spectra in the natural world can be condensed to hues in the rainbow, which only represents simple monochromatic band peak spectra? This is the result of the design of the eye: the three color photoreceptors in the retina (the cones) reduce the information in the light spectrum down to three activity coordinates. Thus, many different physical light spectra converge psychologically to the same perceived color. In effect, for any single color perception, there is a whole parametric space in the power/frequency domain that maps to that one color.

For many power distributions of natural light, the set of spectra mapping to the same color perception also includes a stimulus that is a narrow band at a single frequency; i.e. a pure spectral light (usually with some flat spectrum white light added to desaturate). The wavelength of this pure spectral light that will evoke the same color perception as the given complicated light mixture is the dominant wavelength of that mixture." Quote from: Dominant wavelength - Wikipedia, the free encyclopedia

Also see: http://en.wikipedia.org/wiki/Color

 

[Blackwolf]

My eyes sometimes see 405nm as a grey beam

My eyes also see virtually no difference between 635 and 650

that sucks yo.

 

[Flaminpyro]

It's got to be 404.525nm

 

[Jmillerdoc]

..... I know personally, if there are 5 or 6 "pure [insert color]" threads, I will lose my mind...

Did you hear that? No more pure color poll threads, we cannot afford to lose Bloom's mind here at LPM. It risks lowering the collective IQ of this forum by at least 100 points.

 

[zyxwv99]

I voted for 405nm. Have never seen it in real life, but based on the amount of pictures and the "Wavelength to HEX" tool, I would say that looks spot on violet. At least in my eyes

Thanks for your reply. I don't think it's necessary to have seen a laser of a particular wavelength to have an opinion of what it would look like.

For example, in the "blue" poll, 460 nm won by a landslide, even though most of the respondents had never seen a 460 nm laser. They just knew what 445/447/450 and 473 looked like, even if they had never seen those either. In photographs, 473 looks like sky blue, maybe not the most perfect sky blue, but close enough. People who have seen the real thing agree that this is what it looks like.

Everyone agrees that 445/447/450 is blue with a definite violet tinge. Usually the violet doesn't show up in advertizing photos, but people who've seen the actual lasers swear they see a violet component. The same principle can apply to other wavelengths.

As for wavelength to HEX tools, I've found most of them to be very unreliable. In fact, that's one of my subsidiary interests, figuring out how to connect HEX to wavelengths. Of course they have $20,000 CRT monitors where the red dots are actually 700 nm, but for the rest of us it's the DIY (do it yourself) approach.

So far the best I've found (I think) is this website:

Das Farbspektrum in sRGB / The visible spectrum in sRGB

The author of the website seems to have built a perfectly sRGB compliant device and measured the color with a digital spectrometer, then applied some algorithm to take into account the relative sensitivity of eye to different wavelengths. The numbers are in the column marked "physical." I'm still studying this to figure out how good it is, but at least it's better than just going by simplistic formulas to convert to CIE1931.

 

[Lotus_Darkrose]

I like how this thread is a full page long now and for obvious reasons, has no clear answer whatsoever, just some random opinions.

Can the next poll be what you think the pure sound of a dog's bark is in a single word?

1. Arf
2. Woof
3. Ruff
4. None of the above

 

[hwang21]

Maybe I'm reading this chart incorrectly, but the "CIECAM02" column seems to match the background color much better than the "Physical" column

 

[zyxwv99]

Maybe I'm reading this chart incorrectly, but the "CIECAM02" column seems to match the background color much better than the "Physical" column

Thanks for the observation. I never noticed. However, do you have any idea which one (if any) matches your own experience in working with RGB color? Also, if you mention what kind of monitors your were using, that would help too. (Not brand names, just in general.)

 

[hwang21]

I have no experience with RGB lol I'm the guy who looks at a laser beam and then looks at the webpage on my monitor and sees which column fits best but it does seem like the middle column is fairly accurate, at least with the laser colors I've seen

 

[NightExplorer96]

Thanks for your reply. I don't think it's necessary to have seen a laser of a particular wavelength to have an opinion of what it would look like.

For example, in the "blue" poll, 460 nm won by a landslide, even though most of the respondents had never seen a 460 nm laser. They just knew what 445/447/450 and 473 looked like, even if they had never seen those either. In photographs, 473 looks like sky blue, maybe not the most perfect sky blue, but close enough. People who have seen the real thing agree that this is what it looks like.

Everyone agrees that 445/447/450 is blue with a definite violet tinge. Usually the violet doesn't show up in advertizing photos, but people who've seen the actual lasers swear they see a violet component. The same principle can apply to other wavelengths.

As for wavelength to HEX tools, I've found most of them to be very unreliable. In fact, that's one of my subsidiary interests, figuring out how to connect HEX to wavelengths. Of course they have $20,000 CRT monitors where the red dots are actually 700 nm, but for the rest of us it's the DIY (do it yourself) approach.

So far the best I've found (I think) is this website:

Das Farbspektrum in sRGB / The visible spectrum in sRGB

The author of the website seems to have built a perfectly sRGB compliant device and measured the color with a digital spectrometer, then applied some algorithm to take into account the relative sensitivity of eye to different wavelengths. The numbers are in the column marked "physical." I'm still studying this to figure out how good it is, but at least it's better than just going by simplistic formulas to convert to CIE1931.

Thank you very much for showing me this tool. However I think some of it may be slightly off?

Let's take for example 532nm, 473nm and 650nm:
HEX Tool:
532nm
Your Tool:
532nm

HEX Tool:
473nm
Your Tool:
473nm

HEX Tool:
650nm
Your Tool:
650nm

My eyes see the color as being much more similar to the HEX tool then the tool you mentioned. Not saying this tool is bad, not at all, just having some doubts(myself).

 

[hwang21]

The green looks more accurate with the HEX tool, less accurate with blue, and roughly the same with red. At least that's how it is on my screen

 

[zyxwv99]

I like how this thread is a full page long now and for obvious reasons, has no clear answer whatsoever, just some random opinions.

Can the next poll be what you think the pure sound of a dog's bark is in a single word?

1. Arf
2. Woof
3. Ruff
4. None of the above

Actually, if you look at the distribution of responses, you will see that they are not random. Furthermore, randomness was what I was trying to measure. For other colors, 50% of respondents or more picked a single wavelength. In this one, I was expecting the results to be more random because the vision problems relating to perception of violet.

For every named color, there are usually two named colors on either side. For example, yellow that looks too greenish ceases to be seen as "yellow" and becomes something else like lime green or greenish-yellow. On the other side of yellow is orange, or a little closer, amber.

With violet, the two bounding colors are blue on the up side and gray on the down side. The perception of gray at low wavelengths increases with age, generally as a function of lifetime exposure to uv (usually solar). When you can no longer see 405 as violet you might still be able to see some higher wavelength as violet.

As for the "arf, woof, ruff" question, do you have any idea how many millions are spent every year on exactly that question and others like it? That's how they found out that people in New England are, on average, far more likely to call a color "beige" that people in the Southwestern United States would call "tan." There is also a class distinction: the lower middle class are more likely to call it tan, the upper middle class beige, the upper class ecru.

Besides university linguistics departments, big corporations spend big bucks on this stuff. It's also in linguistics 101.