Transcript Perspective Lecture - ARTS 120

+
Light, Shade, & Value Lecture
Art 120 Drawing 1
+
Basic Vocabulary

Baseline: the imaginary line on which an object or group of
objects sit

Converge/Laws of Convergence: come together,
meet/orthogonal lines will appear to converge at a vanishing
point

Diagonal Lines: straight lines that are at an angle

Forms VS Shapes in Perspective: square/cube; rectangle/box;
circle/sphere; triangle/pyramid; oval/ellipse; cylinder

Foreshortening: a technique for producing the illusion of an
object’s extension into space by contracting its form

Horizontal Lines: straight lines that extend to the left & right

Horizon Line/Eye Level: The apparent intersection of the sky
and earth/The imaginary horizontal line parallel to the
viewer’s eyes
+
Basic Vocabulary

Orthogonal Lines: Parallel lines that appear to converge
at the horizon

Parallel Lines: lines that run together but never intersect

Perpendicular: are lines that intersect at right angles
(90o) to each other

Proportion: comparative relationship between parts of a
whole and between the parts and the whole

Scale: size and weight relationships between forms

Vanishing Point: the spot on the horizon line (or y-axis for
3pt) that orthogonal lines converge upon

Vertical Lines: straight lines that extend upward or
downward
+
Using Value to Create Depth
 General



principles
Know your light source or
sources’ strength and
direction.
Value contrast of objects in
space will become closer
in value to the
background’s value as they
recede in space.
Use different value
schemes to define different
levels of space.
+
Value

Value is describing relative light and dark in order to capture
illusionary volume, mass, space, depth

A simple Value Scale shows figure-ground relationships

Figure-Ground is the condition in which backgrounds tone or
hue changes the visual impact of the figure resting on it. The
same hue or value appears to be a different depending upon the
contrast of tone or hue of the background upon which it is
placed. Conversely, two different tones or hues appear to be the
same when placed on contrasting grounds.
+
The Blur Trick
 Squint
your eyes to blur edges of shapes
and tones in space.
 Tones
will then blend and reveal value
patterns and value schemes.
 This
will allow for quicker layout and
assessment of space in terms of value.
+
John Collier
+
John Collier
+
Understanding Light through
Shadow

There are two types of shadow: Cast and Form

Cast: When an object blocks a light source it casts a shadow. A
cast shadow is not a solid shape but varies in tone and value. The
farther a cast shadow is from the object which casts it the lighter
and softer and less defined becomes its edges.

A form shadow is the less defined dark side on an object not
facing the light source. A form shadow has softer less defined
edges than a cast shadow. Form shadows are subtle shadows
essential for creating the illusion of volume, mass and depth. The
changes in form shadows require careful observation – squinting
at the subject to see value definition affected by figure-ground
making value relationships clearer.
+
+
Intuitive Space - Chiaroscuro

Artists of the Renaissance were concerned with showing
depth and volume unlike the artists of the Middle or “Dark
Ages.” Renaissance artists manufactured the term
“Chiaroscuro” to describe how light and dark can imply
depth and volume. The word Chiaroscuro is a combination of
two Italian words that mean light and dark. (chiaro (clear,
light) + oscuro (obscure, dark)
+
Self Portrait with Gorget
c. 1629 Rembrendt
+
Tenebrism – Dramatic Chiaroscuro

The 17th century introduced a dramatic use of chiaroscuro
called tenebrism. Rembrandt perfected this manner of
Chiaroscuro. Tenebrism made value an instrument of strong
contrast that lends itself to a dramatic and even theatrical
style of using light and dark contrast. The tenebrists were
interested in peculiar lighting causing mood or emotional
expressionism. The deviation from standard light conditions
into unexpected lighting locations creates unusual and
special effects.

Today, this style is often used by photographers.
+
Anatomy Lesson of Dr. Nicolaes Tulp c.1632 by Rembrandt
+
Sfumato

Sfumato, (from Italian sfumare, “to tone down” or “to
evaporate like smoke”), in painting or drawing, the fine
shading that produces soft, imperceptible transitions
between colours and tones. It is used most often in
connection with the work of Leonardo da Vinci, who made
subtle gradations, without lines or borders, from light to dark
areas; the technique was used for a highly illusionistic
rendering of facial features and for atmospheric effects.
+
Mona Lisa
Leonardo da Vinci
c. 1503–1506
+
The Light Side/The Dark Side

Establishing a definite light side and dark side makes round objects appear
round and defines the form of an object accurately. Use this simple trick to
make your artwork more true to life, separate light tones avoiding figureground confusion..

Modeling is a contrived method of drawing the light and dark value to
capture the mass, volume and depth of objects. Rendering is a term used to
describe the actual value and affect of light observed in a form/person, etc.

The lightest spot or streak is where the light strikes the subject in exactly the
middle of the light side between the shadow edge and the edge of the
object. A highlight can be shinny and crisp on a glass or metallic surface, or
fuzzy and muted on a dull or textured surface.
+
+
Types of Shadow –
Core, Midtones, Reflected Light

“Shadow edge” or “core shadow”. The edge where the light is
blocked from the light source is the darkest value on the dark
side. The core or darkest value blends into the middle tones
from the shadow edge on round subjects.

The variable values blended form the shadow edge on the dark
side. Again, the dark middle tones are darker than any values on
the light side. The human eye can trick the brain into believing
the lightest values on the dark side are the same as the darkest
values on the light side. If the artist is confused about lights and
darks, the rendering is less understandable.

Reflected light: If the object being painted is sitting on a white
table, the light from the table reflects back onto the object and
makes the shadow side lighter. If the object of the painting is
resting by something black or dark, the middle values will
become a dark reflection. The concept also holds true when the
object of the painting is sitting on a colored surface
+
+
Cast Shadows

When the source of light is blocked by an object it casts a
shadow. The length and shape of the cast shadow depends on
the placement of the light source. Long shadows are cast from
a side light source (as from the sun in late afternoon or early
evening), and short cast shadows are cast from over head (as
from a noonday sun). The shape a shadow casts depends on
the shape of the object casting it and how close the source is
to the object.
+
Cast Shadow Vocabulary

The vocabulary used to describe cast shadows in art come
from shadow descriptions in astronomy. The umbra,
penumbra and antumbra are the three distinct names given
to the description of shadows cast by heavenly bodies. The
umbra is the darkest part of a shadow considered the
absence of light. The penumbra is a lighter outer shadow
where the object is only partially obscuring the light. The
antumbra is more obscure. When it is visible it seems to
extend out from the penumbra in a lighter and less distinct
way.
+
Light Source, Cast Shadow, and
the Axis

The distance of the object from the light source affects the
appearance of the light and dark side of the object. The
closer the object is to the light source the smaller the light
side appears to that of the dark side. In addition the light
from the light source may appear more cone shaped than a
light source from a distance.

The Axis divides the light side from the dark side and
defines the angle of the light….
+
+
Light Source and Shadow

The shape of the shadow is also affected by the light source.
When the light source is from anything but the sun, like a
light bulb, the shadow widens the further it is from the object.
The sun, meanwhile, casts a “straight” shadow in that it
remains true to the objects shape

More Than One Light Source
A shadow is made for each light source present in a scene. If
you are inside a room, for example, and there are two lights
on, you will cast a shadow from each light source.
+
+
The Sphere
+
The Cube
+
The Cylinder and The Cone
+
More
+
Natural Light – Daylight & Shadow

Cast shadows of irregular
shapes and in natural sun light
are open for interpretation
because of the constant
changing sunlight. As you work
on location, the sun will
continue to advance and
change while you are drawing.
Note the place you want the sun
positioned and keep that
constant, to avoid a confusing
spread of shadows. The nature
of shadow is affected by
weather, sunlight, moonlight, or
artificial light.
+
How this works…..
+
Basic Forms – SEE just don’t Look
+

Tips to keep in mind:
-The darker the shadow, the brighter the light source.
-As the shadow is drawn further from the object, the lighter it
becomes.
+
Student Work
+ 1-Point Perspective
+
2-Point Perspective
+
3-Point Perspective