Art Foundations I

Value

Value Lecture

Notes

VALUE: The relative degree of light or dark

Terms Used in discussing Value:

Achromatic value - (relating to differences of light and dark, without regard for hue and intensity.
Cast shadow - ( the dark area that occurs on a surface as a result of something being placed between that surface and a light source.
Chiaroscuro - ( 1. Distribution of light and dark in a picture.2. A technique of representation that blends light and shade gradually to create the illusion of three-dimensional objects in space and atmosphere.
Chromatic value - (the relative degree of lightness or darkness demonstrated be a given color
Decorative value - ( value stressing the essential flatness of a surface
High-key value - ( a value that has a level of middle gray or lighter
Highlight - (the portion of an object that, from the observerís position, receives the greatest amount of direct light
Local value - ( the relative lightness or darkness of a surface seen in the objective world, that is independent of any effect created by the degree of light falling on it
Low-key value - ( any value that has a level of middle gray or darker
Shadow, shade, shading - ( the darker value on the surface of an object that gives the illusion that a portion of it is turned away from or obscured by the source of light
Shallow space - ( the illusion of limited depth. With shallow space, the imagery moves only a slight distance back from the picture plane.
Value distribution - ( the proportion and arrangement or organization of values that control compositional movement and create a unifying effect throughout a work of art.

Important elements of value for students to understand:
The definition of value( the difference between value and color
How it creates emphasis and distinguishable shapes

We see because of the relative presence or absence of light, but light is not uniformly shed on the environment. Light goes around things, is reflected by shiny sufaces, falls on objects which themselves have relative lightness and darkness. Variations in light or value are the means by which we optically distinguish the complicated visual information in the environment. Through our visual perseption, our eyes are equipped to perceive hundreds of subtle differences in value in nature.
But we are limited when we reproduce the variations in value in a 2-d medium. We are limited to a value scale of about 13 values form light to dark, this can be pushed to around forty, but it is still limited compared to our own visual perception.

In our discussions we are going to be concerning ourselves with achromatic values (relating to differences of light to dark, without regard to hue and intensity).
We will address color at a later date in more specific detail.

The difference between color and value:
When dealing with color we use the term chromatic value (the relative degree of lightness and darkness demonstrated by a given color), this is not to be confused with the colors hue, which refers to where the color falls along the colorwheel.

High-key value- a value that has a level of middle gray or lighter
Low-key value- a value that has a level of middle gray or darker

Value has weight( in composition value contains a certain amount weight or strength (drawing more of your attention than other values).

The perceived strength of a value is in direct relation to the surrounding values in the compostion. (if it is a low-key composition( a high-key value will draw more attention, if it is a high-key composition( a low-key value will draw more attention)

This relationship between values can be subtle or more abrupt, it is more easily noticed in the latter situation.

We understand the form of an object by the way we perceive light to interact with it, creating value.

Even gradation evokes a sense of a gently curved surface. (sphere, cylinder)
And abrupt change of tone indicates a sharp or angular surface. (squares, rectangles, etc)

Terms for illusionistic value

Highlight-
Cast shadow-
Reflected light
Shadow edge
Light
Core shadow