Rendering Color I

Rendering Color I

“What is color? No object of itself alone has color.
We know that even the most brightly colored object, if taken into total darkness, loses its color. Therefore, if an object is dependent upon light for color, color must be a property of light.
And so it is.”
Paul Outerbridge, Photographer 1896 – 1958

As Mr. Outerbridge so succinctly states, color is a property of light…or, otherwise put, a function of light.  Color and light are intrinsically entwined…part and parcel of each other… mystic twins, or co-dependents, depending on your point of view.

Sunlight, or white light,  is the combination of the entire electromagnetic spectrum ( a light source’s spectrum is a distribution giving its intensity at each wavelength, and most light sources emit light at many different wavelengths)..in essence, all the colors of the rainbow.  Their combination creates white light, while  lack of light, no color, is perceived by us as black.  Though artists may see black as a color, it is actually the lack of color: a state of no color.  We are discussing color, and color mixing from the point of view of light wavelengths, not color mixing as regards to paints.  This is physics…the physics of light and color.

The terms “color” and “wavelength” here may confusing.  Our eyes will perceive the color based on not only the wavelengths of light that the object we are viewing reflects or absorbs, but  also on the actual measurement of those wavelengths…measured in nanometers. We can see the reflected colors of light which lay in a very small region of the electromagnetic spectrum called, aptly enough, “visible light”.  We cannot see color wavelengths that are absorbed by an object or surface.

Wavelengths ranging from about 400-750 nanometers make up the visible spectrum of light that can be perceived by the human eye.  When light strikes an object certain  of its wavelengths are absorbed by that object, and others are not. Those that are not, those wavelengths of light which bounce  or are reflected off an object, are perceived by the human eye as color.   In essence, “An object appears a certain color because it reflects certain light wavelengths, which are then  perceived by the eye.”  —http://www.wisegeek.com/what-is-the-color-rendering-index.htm

Surfaces we see as black absorb all of the wavelengths of light in the visible spectrum which reach them.  All the “color”  thus is absorbed, and we see no color, and thus black. Surfaces we see as white are reflecting, or bouncing back to our eyes, (specifically, the rods and cones -photoreceptor cells- within our eyes), all of the wavelengths of visible light which reach them.  Thus, as all of these visible wavelengths are being reflected “to us”, and their combination, as discussed above, creates white light, as white light (discussed above)  is the combination of entire electromagnetic spectrum, or all the colors of the rainbow!  (Mind you, if you mix a wide spectrum of varying paint colors together, you will  not get white! We are discussing color in reference to light only in this post!).

Each light source emits different wavelengths of light, thus the way we perceive colors varies depending on how the object we are seeing is illuminated, I.E., the wavelengths of light it absorbs and reflects.

Ah..now we begin to get to the heart of the story…the Color Rendering Index, or CRI.  It will take a second post on this complex subject to further demystify it.

“The Color Rendering Index is an international measurement scale that describes how colors are rendered under an artificial source of light. The standard against which artificial lighting is compared is daylight, because daylight renders the widest variety of colors. Artificial lighting, by contrast, can render very many or very few colors, depending on the nature of the light source. The color rendering index has many applications, especially in art and photography.” —http://www.wisegeek.com/what-is-the-color-rendering-index.htm

“The Color Rendering Index (sometimes called color rendition index), is a quantitative measure of the ability of a light source to reproduce the colors of various objects faithfully in comparison with an ideal or natural light source. Light sources with a high CRI are desirable in color-critical applications such as photography and cinematography.^[1] It is defined by the International Commission on Illumination as follows:^[2]

Color rendering: Effect of an illuminant on the color appearance of objects by conscious or subconscious comparison with their color appearance under a reference illuminant.

The CRI of a light source does not indicate the apparent color of the light source; that information is under the rubric of the correlated color temperature (CCT).” —http://en.wikipedia.org/wiki/Color_rendering_index

Because of the complexity and relative “thickness” of this subject, I will delve further into the Color Rendering Index, Color Rendering itself, The International Commission on Illumination, and Correlated Color Temperature, in a subsequent post.

Until then…I am wishing you much light and color in your life.  May your spirit be illuminated, and your soul rendered…in all the colors of the rainbow!

Shedding Light on Color

Shedding Light on Color

What is color really?

We tend to think of color as being a property of, a part of, or existing within or on something.  We think of an object or surface having, or containing color.  As color is so emotionally, psychologically and even physically powerful, we concretize  it, i.e., we  see it as a Thing, unto itself.

But actually, as IACC color designer Frank Mahnke says, “Color exists only in our brain.”  He further explains, “Color is actually the result of different wavelengths of light stimulating certain parts of the brain. The experience of color depends on the intensity of light, the way it is reflected from a surface, and the colors surrounding objects.”

The Artist’s handbook of Materials and Techniques by Ralph Mayer states, “Each paint pigment owes its color to the kind of light rays it absorbs and reflects.  White light (daylight) is composed of a number of waves or impulses of various dimensions or wavelengths, any single one of which, if isolated, would have the property of producing a specific color sensation on the eye.  When a ray of white light falls upon a pigment, the pigment absorbs certain waves and reflects others; this determines its color effect.”

When we consider that white  light is composed of the color spectrum, we can then understand that the color that we see is composed of the light waves that are NOT absorbed by the surface we are looking at.  This may seem counter-intuitive, because aren’t we looking at a color that IS part of the surface we see, and not the color that isn’t?

Well, actually, no.

We are perceiving a color that is, to a great extent,  the light wavelengths NOT being absorbed by the surface, which ARE being scattered, or reflected “back to us”, and thus we perceive the surface as “being” that color that we see.  I say “to a great extent”, because our perception of color  is also affected  by ambient lighting, as well as the color of objects nearby.

When we think of the surface (actually, it is the material, or pigments on or in the surface, but for the sake of simplicity…) as absorbing the light waves we DON’T see, and reflecting back to us those we DO, then the whole phenomenon becomes a bit easier to understand.  In a sense, the colors we see are not really “there”, objectively speaking.  Indeed, one might say that our perception is a phenomenon of light.  Comprehending this, we can understand why the Impressionists declared that they were “painting light”.

However much we study the science, the facts as we understand them, and various color theories from Newton to Goethe, there is an aspect of color that remains a mystery, and perhaps rightly so.

The fact that color is not an inherent part of objects, but is, among other things, an effect of light, which is mutable, changes our perception of both ourselves and the world around and within us.  Our comprehension is tweaked, and may become  just that much broader.  Learning about, experiencing, and understanding aspects of color may color our view on hue, the world, our lives.  Color, and the art, science and magic of it really can be transformative; white light splintering into all the colors of the Rainbow…

What scientifically magical or mysterious aspects of color have YOU discovered lately?

If you are so moved, please share them with us here.  We love to hear from You.

Remember, we are all coloring our way through this thing called Life, together