Color and Light - Light and Form Chapter 3

LIGHT AND FORM

             The Form Principle

            "... the analysis of nature in terms of geometrical solids, which can be rendered according to laws of tonal contrast." James Gurney

When light hits a familiar shape it creates a series of recognizable patterns with the shading. Understanding and identifying them helps to ground them in the reality of our artwork. 
Direct sunlight: Strong division of light
Overcast light: More diffused light 

In the shadow is not just blackness; other sources also cast their effect on the shadow. 

Vocabulary: 

• Terminator(ie. the bedbug line): transitional area from light to shadow. In direct sunlight, this line will typically be sharp; in overcast light it will be larger with more transitional light. 
• Occlusion Shadow: darkest part of the shadow
• Core Shadow: Usually just beyond the terminator, darkest part?
• Grouping planes: the practice of simplifying shapes into distinct similar planes to emphasize simplicity. 

Location of the Terminator

Texture is very hard to see in darkness - it is emphasized mostly in the darker halftone. 

In diffused light, there is not really any clear, distinct shadow- the light is just mostly focused on the planes turned upwards. The tone of the light might become cooler or softer based off of what it reflects off of. 

             Separation of Light and Shadow

Our mind interprets what we see to help us make sense of the world around us. However, sometimes it tricks us when we see shadow so that we see some things as darker or lighter than they really are.

Square A is the same shade as Square B.
Wikipedia

It is important to be mindful about the tonal differences when transitioning from light to dark.


             Cast Shadows

Cast shadows are full of other light reflecting from various sources; they aren't super duper black. Often in the sunlight, cast shadows are blue because they reflect the blue of the sky. Hard lights will cast sharp cast shadows; soft lights will cast soft shadows; the edge of every shadow becomes more fuzzy the further the shadow is from the object that is casting it. 

             Half Shadow

Half shadows add a sense of drama - the colors in the light will appear brighter and warmer than the colors in the shadows; even whites. 

             Occlusion Shadows

Occlusion shadows are shadows formed by the closeness of two objects; either touching or not, and can be found in a room where two walls meet. Often they are in clothing or close to the ground. They are also known as crevice shadows. 

Anim Bizz
Occlusion shadows in between the creases of the face, etc.

             Three-Quarter Lighting

Usual portrait lighting; typically both eyes have light. There is a small shadow from the nose onto the cheek, but the rest of the cheek has light (other than the very far side). 

             Frontal Lighting

Light shining directly at the form from the viewer's perspective. There is very little shadow, no matter how bright the light is. Shadows will appear on the face but they are small. This kind of lighting is awesome for showing off color or pattern - because the shadows are very few. There is a small outline around the form as the planes fall away from the light. 

Abe Lincoln bust - on the left is frontal lighting.

             Edge Lighting 

Also called rim light or kicker. Light comes from behind to illuminate the form it comes around.

William Sawalich

Usually occurs outside when the sun is going down.

Typically edge light is not a single rim around an object - the planes of the object that catch the light are going to reflect light so you can see. (see above image)

             Contre Jour

Contre Jour is backlighting when the object of the painting usually blocks the light. It has a similar effect to edge lighting, with the exception that the light is more diffused across the form around the edges. The edges of such forms lose detail and the shadows are coming toward the viewer. 

Contre Jour light is less harsh than edge light, and illuminates more of the figure than edge light does.
Unknown Artist (Pinterest)

The background doesn't need to be purely white, just hazy, since the light is coming through the background. 

             Light from Below

There is a general association of underlighting with firelight, which creates drama and intrigue. They will often have a lot of color depending on the source.

Underlighting
Bella120

Underlighting can have a warm, or a colder effect. It is able to make faces unrecognizable, since we usually see faces lit from above.

Frankenstein
ECG Productions

One way to create size in an object is to have the light shine brightly on one part of the object and then fall off towards one side. This works well with underlighting if you want to convey size, because the light starts towards the bottom when the object is closer to the light source, and falls off towards the top as it goes away.

             Reflected Light

Reflected light bounces off of objects and falls onto others in nearby vicinity. When light is reflected it reflects its color as well. 

Reflected Light
James Gurney

Shadows are generally going to be the color opposite of the light that shines on them. Shadows also reflect the light they catch, which means that their color (based on the light they are catching) can also change. For example, most shadows are blue because they are reflecting the sky, and their light source is the sun. However, as in the painting below, the shadows on the ceiling of the library porch are yellow because they reflect the light of the porch below. 

Millbrook Library
James Gurney

Toledo Alley
Dai Wynn
The shadows found in this painting reflect a strong orange color because they are reflecting light off of the red buildings. The street reflects blue because it is only reflecting light from the sky.

James Gurney's 5 Truths about color in reflected light:

             1. In shadow, upfacing planes are cool, and downfacing planes are warm. 

             2. Reflected light falls off quickly as you get farther from the source, unless the source is very large.

             3. The effect is clearest if you remove other sources of reflected and fill light. 

             4. The color of the shadow is the sum of all the sources of reflected illumination, combined with the local color of the object itself.

             5. On a sunny day, vertical surfaces in shadow usually receive two sources of illumination: warm ground light and blue sky light. 

             Spotlighting

Spotlighting is used to highlight a certain part of a composition to point the viewer's attention to that section. This helps emphasize the important action and downplays the less important things. The rest of the composition usually falls into shadow.

In the Spotlight
Anne Blair Brown
In this piece, the light falls specifically on the stove and the window, and almost nowhere else. 

Ambient light is the light left in the scene after the spotlight is removed. This kind of lighting can also be used on small forms, like faces, to highlight eyes or important parts of the face.

             Limitations of the Form Principle

While most solid objects follow the form principle, many other things do not. 

Clouds are one of the exceptions to the rule. They are each different and can have multiple sources of light. They pick up less light from secondary sources than they transmit to their shadowy side, through internal scattering. 

Foliage, like on trees or bushes, also behaves strangely in light. Pay attention to how much light passes through the trees versus to the shadows to realistically recreate lighting in paintings.