[M4D deal ALIVE] Lumintop GT micro

So is snow a different color in different countries?

Hmmm… I think snow is cold white by definition… :wink:

You mistake the colour of a reflecting object (snow, wall, a picture) with colour of a light source, that is a complete different thing.

What determines the colour of a reflecting object, like snow, or a plastered wall, is what percentage of each wavelength of light is reflected, if that percentage is close to the same for all visible wavelengths, and reasonably high, above say 80%, the object is called white. But what colour you actually perceive is totally dependent on what light you illuminate your snow with: snow is cool white if you illuminate it with a cool white flashlight, and warm high CRI if it is illuminated with an evening sun. Or red in your car’s breaking lights.
So for objects to be called white they must not alter the colour of the light source you illuminate it with too much, the object does not “make” its colour by himself, instead it can look any colour depending on what light you shine on it.

The colour of a light source is a complete different story, for a light source to be called white it must have a certain mix of wavelengths so that all three types of colour receptors in your eyes are stimulated within a certain ratio, and then you see white. But that ratio is variable, there is an extreme wide variety of spectra that are perceived as white, and what you think is white can depend on what light you were experiencing a minute earlier, white depends on your mood, and even what culture you are from. White light can not be defined, it changes from person to person, and within one person it changes by the minute. That is why I ironically responded to teacher with the concept of True Neutral Whitetm :slight_smile: , because it can not possibly exist as a fixed thing, just as a passingly perception in one’s mind (and even as an experienced photographer who knows the pitfalls, the perception of what is “white” still varies in your mind) .

Try telling that to your wife when shopping paint at Lowes :slight_smile:
Pure white to me is Taylor Swift….now That girl is pale….and not sure how pure……LOL

By definition, white (in regard to light) is equal amounts of all colors. There actually IS a standard. And for me, as a wedding photographer, a light that allows a multi-thousand dollar white dress to still look white is a white light. When it comes to this industry, which is Billions of dollars a year, the definitions are exacting. :wink: (now, if only I could get a nice share of the Industry… but alas, I live in a small town and people seem to believe their phones are adequate for taking pictures)

True Neutral Whitetm

So it does exist….

I never heard such a definition, but at least what “all colours” and “equal amounts” are should be explained if this is a definition.

What Colors Make Up White Light / search results

…………

Colours of Light

Light is made up of wavelengths of light, and each wavelength is a particular colour. The colour we see is a result of which wavelengths are reflected back to our eyes.

Visible light

Visible light is the small part within the electromagnetic spectrum that human eyes are sensitive to and can detect.

Visible light waves consist of different wavelengths. The colour of visible light depends on its wavelength. These wavelengths range from 700 nm at the red end of the spectrum to 400 nm at the violet end.

White light is actually made of all of the colours of the rainbow because it contains all wavelengths, and it is described as polychromatic light. Light from a torch or the Sun is a good example of this.
…….

http://science.answers.com/Q/All_of_the_visible_color_light_waves_together_make_up_white_light

  • White light is made up of all the colors of the visible spectrum. If we drop back to the idea of the colors of the rainbow, the red, orange, yellow, green, blue and violet, we’ll have the colors. The colors making up white light are all the colors from red to violet. Said another way, all the colors of light from the infrared to the ultraviolet make up white light.
    White light is made up of every other color of light. Blue, red, yellow, orange, everything. When these colors of light are combined, they form white light
    …….

http://science.answers.com/Q/What_aggregation_of_light_colors_make_up_white_light

All the colors of the visible spectrum make up white light

  • °White light is a balance of all the wavelengths (colors) of visible light: Red, Orange, Yellow, Green, Blue, Indigo, and Violet, the same colors and order of rainbows.

By these answers that is not a great website it seems if you want an answer for your scientific question.

The answers that you quote are vague, terms are undefined, the information is incomplete and some information is wrong. In other words: the question is not very scientifically answered. One example: light from a CFL tube can be perfectly white, even very high CRI, and yet the spectrum is a bunch of discrete peaks, most wavelengths in the visible spectrum are prety much absent.

Why are you complaining on ‘white’?
From what I’m aware off, white is the abscence of all colors.

Black is the absence of all colors, they are all absorbed into a black body and nothing reflected hence no color to see. White is the presence of all colors, nothing absorbed.

Hey I’m just doing the best I can with what I have to work with, I’m not even close to a scientist. Like old Forrest Gump, I’m not a real smart man.
I’m just throwing out some ideas against the wall to see if anything will stick.

Back to the ole’ drawing board I guess for me…… :person_facepalming::wink:

But I truly am interested in the true definition / meaning of white light.

If it is not…. “White light is a balance of all the wavelengths (colors) of visible light: Red, Orange, Yellow, Green, Blue, Indigo, and Violet, the same colors and order of rainbows”. …… what is it?

White light is defined as the complete mixture of all of the wavelengths of the visible spectrum. This means that if I have beams of light of all of the colors of the rainbow and focus all of the colors onto a single spot, the combination of all of the colors will result in a beam of white light.

True or not true?

At some point I wonder if it really matters that we understand HOW white light is made, I mean, after all, WE are not the ones making emitters or the phosphor that drives them. We merely buy what is available to us, which oftentimes is not the best tint. Not to mention that WE don’t control the AR coatings that go on a lens and more often than not skew the tint of our prize emitters. So, is it us that needs to understand, or the people that actually have control over the items we buy?

Seriously, teacher, we already have ONE ROCKET SCIENTIST here, he can’t get it right either apparently… look sharp, ie: focus and diligence achieves the ultimate success. Or does it? Luck favors the blissfully ignorant. :wink:

How ’bout 18% gray?

:student::+1:

If it’s called grey (or gray) it isn’t white. :wink:

Edit: Then it’s just a dirty joke. :slight_smile: (A WHITE horse fell in a mud puddle. my son’s idea of a dirty joke)

Signed up for 1 NW.

Thanks

:beer:

Any news yet?