Nov, 2: Color and Light Chapter 3:Light and Form

The Form Principle:
One of the things that I have noticed while reading this chapter of Gurney's book is the emphasis he places on doing things to stay true to the rules of light and color, but also the importance of giving your art the impact that it necessitates.
One of the quotes that demonstrates this is, "Keeping the Core intact--or painting it in even if you can't see it--can give the form more impact." In the same section where he says this he also talks about how you do not have to draw in every single shadow texture when a plane is in full shadow.

Half Shadow:

In this section he says, "One way to create drama, especially with a vertical form, is to light the top half and lave the rest in shadow" Here again is the theme of impact and creative liberty.

Occlusion Shadow: Shadows that occur wherever two forms touch each other or wherever a form touches a floor.

Three-Quarter Lighting:
This is the traditional lighting for portraiture art. A light source is placed about 45* from the face and then a secondary Fill Light, or natural light,  is also used to insure that the face is able to be seen.

This painting uses both a key 3/4 light and the natural light as a fill light. 

Short light can also be used to push the shadow of the nose further across the cheek and help make the face look thinner.

Frontal Light: (Here is a paragraph from the book) 

"Frontal lighting emphasizes two-dimensional design instead of sculptural form. It's a good lighting to choose if you want to emphasize local color or pattern--to features. fashion or costume, for instance. And I;s one of the few times when outlines actually appear in real life. The outline is really  the thin fringe shadow that appears at the very edge of the form. That line deserves close study. It varies in weight in proportion to the width of the plane that is turning away."

Edge Light:

Edge Light is not just a thin white line around the form. The width of the rim light varies according to the size of the planes that face backward to the light. 

Contre Jour: 

One approach to Contre-jour lighting is to think of the light area behind the subject not as flat white paint but as a sea of vapor, with light streaming out of the background, melting away the edges of the form. 

It's often effective to keep a little color in the background haze, and to lower it a bit from white. 

Light from below:

Three points about lower lighting:

1. Sources of light that shine upward are often strongly colored, either with the warm orange flow of firelight, or with the blue flicker of a computer screen.

2. One way to make something look large in a nighttime setting is to have the light shine on just part of the form and fall off rapidly. 

3. Building a small maquette, or model, makes it easier to experiment with actual light. 

Reflected Light:

Conclusions about reflected Light:

1. upping shadow planes are cool and downfacing planes are warm

2. Light that is reflected falls off quickly unless coming from a large source. 

3. The effect of a reflected light source is clearer if you remove the other sources of reflected/fill light. 

4. Shadow colors is the sum of all of the light color that is hitting it, as well as the local color of the plane.

5. On sunny days, vertical planes generally receive both warm ground light and blue sky light. 

Spotlighting:

The shadow should match the color to the surface ahead of the spotlight beam, because it is receiving the same ambient light as the rest of the scene.

Limitations of the form principle:

Materials such as clouds, foliage, hair, glass, ad metal behave differently than solid objects with matte  a finish. 

-Clouds transmit a greater amount of light to its shadow Side because of internal scattering than they do from picking up reflected light from secondary sources.