Gradations and Progressions

Gradation: 

Reilly uses the term gradation to describe a gradual change in value over a flat surface; side to side, top to bottom or diagonally, notably on the background. It is a minor effect of light and can help show the position of the light source, and how far the subject is from the background. 

The nearer the light source to the background, the greater the degree of gradation.

Keep the degree of change modest, or the background will begin to look three-dimensional and detract from the form of the subject. Think of gradation as both a natural effect and a design element.

Progression: This term describes the degree of change in a form as it progresses out from the picture plane towards the viewer or recedes away from the viewer. The greater degree of change, the more attention it will receive, and the more it will appear to project toward the viewer. Conversely, the lesser degree of change the more the object will seem to recede. Hard edges help an object project, soft edges help it recede. High value contrast help it to project,  minimal contrast helps it to recede.  Reilly emphasizes that the changes in value should be made to the object, not the background.

© John Ennis 2011

Next Topic: Color Vibrations

Basic Planes

By simplifying form into planes, it becomes easier to understand and see how light affects form. There are four basic planes: front or upright plane, side(edge) plane, top plane, and under plane.

Top planes in the light

Always go 1 value higher than average 

More neutral than the average

Picks up the hue of the light source (e.g. in north light would shift towards blue)
Use hard edges

Under-planes in the light -

1 half value darker than average 

1 & 1/2 value darker than the top plane

Soft edges

Avoid going too dark

Top planes in the shadow 

1/2 lighter than average in the shadow

Soft edges
Can be more neutral

Under-planes in the shadow 

One half value darker that the average in the shadow
Can be illuminated by reflected light resulting in hue, value and chroma changes

No hard edges, edges  are soft all over

It is the angle that the plane presents to the light source that determines its value.

Translate the idea of planes back into painting form.

The Edge Plane:
The front plane is usually more chromatic than the side plane, especially with skin. The edge plane drops slightly in value and chroma as it bends away from view, due to the texture of the skin containing pores and hair follicles. This can be exaggerated when necessary. A shiny surface might produce a different result, where reflected light might increase the chroma.


© John Ennis 2011


Next Topic: Progressions & Gradations

The Effect

Rembrandt (Rembrandt van Rijn)  Self-portrait  www.metmuseum.org

In Reilly's words, "The effect is where you look first, it is where you want the viewer to look. It is a guided tour that is planned by the artist, the looking device used by the Masters."

Reilly used the term "The Effect" to describe how the effectiveness of light on the subject can be used to the artist's advantage. By emphasizing the position and brilliance of the light source, the viewer's eye can be directed to a chosen area of interest. Exaggerate this principle from the beginning. Include it in your color note.

Look for it in the area nearest the illumination, the largest, lightest area of the form. The plane that faces the illumination. In life class this might be the upper chest of the model, but depending on the light source it could also fall on the hips, shoulder, head, etc. Consider it an element of design that increases form and volume to the subject. Think Rembrandt! 

It is most often a value problem. Within the light area there is a concentration of light due to the bending away of light. A light source creates a cone of light whose strongest illumination is in the center, allowing a gradual fall off. This concentration of light creates an area in the light which is lighter in value than other areas in the light, thereby creating even more contrast with the shadow. A focal point created by illumination. To make this effect of light work, create the greatest contrast in this one area by allowing a greater range of values here. Be careful not to repeat this range of values anywhere else on the figure or object.


© John Ennis 2011

Next Topic: Basic planes

Highlight

Look for the highlight on a sphere, like the ball of the nose, on corners, like the edge of the nose, and in corners like where the side of the nose meets the cheek . On the crest of a rounded form inside the center light. On the skin where the surface changes to wet (sweat) or oily. Usually a full value lighter than the form on which it sits.

Paint the highlight in as a teardrop that flows with the action. Shaped like a comet.

It can have soft edges on skin, or hard edges on metal. 

Shifts toward the hue of the light source. The highlight is a reflection of the light source (the skin is not a perfect reflector).

It is an interest-getter.


© John Ennis 2011

Next Topic: The Effect

Center Light

The center light is the main modeling factor out in the light. It takes the flatness out of the  planes in the light area. It makes form out in the light.

It is found only on round forms. 

It is a half value lighter than the average light value.

There are no hard edges on the center light. 

The center light is found and used most effectively on the upright plane. 

It widens and narrows with the form.
Create the center light on big forms first, then break in into smaller forms.

If the average in the light is 7th value, you can  lay in the center light a full value lighter and brush it down on all sides to soften and darken it to 7 1/2. Remember the highlight will be a full value lighter than the average, the center light has to be in between. There is no hue change, hold the local. There is no significant chroma change. It might be slightly weaker, but making it too neutral will weaken the edge plane (edge planes is a subject for an upcoming blog segment).

Once the curved form becomes a corner, the modeling factor
becomes a highlight, not a center light. 

Shape of the form dictates shape of the center light.

As the thumb turns towards body,
the forearm twists and the center light follows. 

In the illustration below, Reilly indicates a step-by-step procedure for painting the center light. After laying-in the light, shadow and halftone, add the center light, softening the edges as needed. Then add the cast shadow from the jaw. 

Try this exercise at home. 

© John Ennis 2011

Next Topic: Highlight

The Halftone

The halftone is the modeling factor found between the light and the shadow. As a plane it is at an angle to the light source, receiving just enough light to keep it out of the shadow.

The value scale:

White is our lightest local color. A white bed sheet is lighter in value than a yellow sheet. An orange sheet would be darker yet, but still lighter than a black sheet. In typical indoor lighting, white is painted at value 10 in the light and 4 in the shadow. Black is our darkest local color. It is painted at value 4 in the light and 0 in the shadow. All other colors in the light will remain above 4, since they are locally lighter than black. All other colors in the shadow will be darker than 4 since they are locally darker than white. The halftones fall between values 7 & 2. Spend some time and thought considering this concept of value scale, it's role is crucial in representational painting.


Locals:
It is important to understand the idea of locals. It is the local quality of a white shirt that it is lighter than a gray tie. And a gray tie is lighter than a black vest. And they should appear that way under any lighting condition. A white shirt (a local of 10) is painted 10 in the light, has a halftone of 7, and is painted 4 in the shadow.  A middle value gray tie (whose local is 5) will be painted value 7 in the light, 4.5 in the halftone, it's shadow at 2. It follows that the black vest (a local of 0) is then 4, 2 and 0 respectively. 

Halftone Factors:

Surface texture: a mat surface catches and diffuses the light. A nap surface with many tiny bumps creates even more halftone. A shiny surface, with no texture to capture light, has no halftone.

Light level: A strong light creates less halftone, a weak light creates more.

Light source: a point source (light bulb, sun, photoflash) creates less halftone. A diffuse light source (north light, overcast day) creates more.

Form: Round, soft forms have more halftone. Hard, bony forms have less.

Brushing:

As a rule of thumb, it is good to keep the halftone narrow, since a wide halftone can ruin the form. If the halftone is narrow you can brush for it, meaning you can take a brush, zig-zag it through the adjacent light and shadow stokes, and brush back over the the zig-zag (see above). If this deadens the chroma, you may have to restate the halftone with more chroma and repeat.

Figure Painting:

Squint down at the halftone and determine if it masses with the shadow or with the light. Using Reilly's indoor palette, if the shadow is painted in at value 3, then the halftone will be painted at value 4 if it masses with the shadow, and at 5 if it masses with the light.

© John Ennis 2010

Next Topic: Center Light

The Lay-in

Paint Application

The lay-in is the initial application of opaque paint, wet paint brushed onto a dry wash-in. If your wash-in values are accurate, you've established a good foundation for your lay-in.  Reilly offers a specific sequence for this crucial stage in painting. Begin with known quantities. The absolute darkest dark, called the accent, where no light exists is painted first, using black warmed with a little Alizarin Crimson.  It is easy to spot and gives the painter a good parameter to start with on the dark end of the value scale. It will help determine the value of the shadow. Next paint the shadows, lights, halftones, highlights and finally reflected light.

3 Parts to a Picture

Simply put, the background is flat and should stay behind the figure. 

For the form of the drapery, mix two lights (top, and front planes) and one shadow.

For the form of the model, use three lights, one shadow.

Action

Brush paint on first with the action first, then with the form. 

Brush the paint onto the planes.

Massing

Initially try to combine all of the areas in the light into a simple graphic shape, ignoring small shapes and isolated darks in the light. Make a similar massing in the shadow, ignoring isolated lights in the dark. This will help establish the action.

The Effect of Light

In a typical indoor setting, the part of the figure closest to, and at a perpendicular angle to the light source is five values lighter than the shadow. The part of the figure at a somewhat oblique angle to the light source, the darkest light, is 3 values lighter than the shadow. The effect of light is the result.

Factors affecting the light on the  form

Size has little effect, but the amount of light, distance from the light, and angle towards the light are relevant. Also the texture, and the difference between locals.

From Reilly's notes:

The success of a painting is due to the lay-in. 

The putting down of paint so as to execute the final stage. 

The paint mixed and put down are called averages. 

The correct averages make a condition called the poster. 

The lay-in sets the complexion of the model.

The averages are the local condition in chiaroscuro (light-shadow) 

-so each local is to be mixed in light & shadow 

-the poster is the look of the chairoscuro together as a pattern.

© 2011 John Ennis

Next Topic: Half-tones