Docstoc

Colour _ Lightning

Document Sample
Colour _ Lightning Powered By Docstoc
					SESSION 3. COLOUR & LIGHTNING

To paint well is simply this: to put the right colour in the right place. — Paul Klee

Colour and lighting in images (paintings, drawings, illustrations, watercolours,
photographies, movies…) What a vast issue! Let’s see some clues about the
thing… first, something about physics

WHAT IS LIGHT?

Light is usually defined as that portion of the electromagnetic spectrum visible to
the average human eye. It is commonly called “visible light” and subdivided into
seven major colours—red, orange, yellow, green, blue, indigo, and violet.
Visible light lies on the electromagnetic spectrum inbetween infrared and
ultraviolet light.

Electromagnetic radiation is characterized by its wavelength (or frequency) and
its intensity. When the wavelength is within the visible spectrum (the range of
wavelengths humans can perceive, approximately from 380 nm to 740 nm), it is
known as "visible light".

A nanometre (American spelling: nanometer, symbol nm) (Greek: νάνος, nanos,
dwarf; μετρώ, metrό, count) is a unit of length in the metric system, equal to one
billionth of a metre (i.e., one millionth of a millimetre).

Rainbow: The light is first refracted as it enters the surface of the raindrop,
reflected off the back of the drop, and again refracted as it leaves the drop. The
overall effect is that the incoming light is reflected back over a wide range of
angles.




The colour of an object depends on both the physics of the object in its
environment and the characteristics of the perceiving eye and brain. Physically,
objects can be said to have the colour of the light leaving their surfaces.



                                                                                   20
Primary colours are sets of colours that can be combined to make a useful
range of colours. Media that combine emitted lights to create the sensation of a
range of colours are using the additive colour system. Typically, the primary
colours used are red, green, and blue.

Adding primary colours, we obtain other colours. Adding all together, we obtain
white light. White light is the sum of all colours.

Television, monitors and theatre lighting use the additive system to make
colours. So they use the RGB model. (Red, Green, Blue).




Secondary colours (Or Subtractive primary colours)

Note: A secondary colour is a colour made by mixing two primary colours

They are Magenta, cyan blue and yellow. When we combine them, we subtract
light. Ideally, the combination of all of them produces black. Black is the lack of
light.




Painters and art students use the subtractive system when they combine the
pigments of oil or gouache. Newspapers, magazines use the subtractive model.

Note that in a subtractive model, Red Green and Blue are secondary colours.


Mixing yellow and cyan produces green colours; mixing yellow with magenta
produces reds, and mixing magenta with cyan produces blues. In theory, mixing
                                                                                21
equal amounts of all three pigments should produce grey, resulting in black
when all three are applied in sufficient density, but in practice they tend to
produce muddy brown colours. For this reason, and to save ink and decrease
drying times, a fourth pigment, black, is often used in addition to cyan, magenta,
and yellow.

The resulting model is the so-called CMYK colour model. The abbreviation
stands for cyan, magenta, yellow, and key—black is referred to as the key
colour, a shorthand for the key printing plate that impressed the artistic detail of
an image, usually in black ink.



THE CHROMATIC CIRCLE OR COLOUR WHEEL

A colour wheel or colour circle is an organization of colour hues around a
circle, showing relationships between colours considered to be primary colours,
secondary colours, complementary colours, etc.

It is a way of arranging the colours. It is based on Physics colour theories, that
began in 18th century.




RYB make up the primary colour triad in a standard colour wheel; the
secondary colours VOG (violet, orange, and green) make up another triad.
Triads are formed by 3 equidistant colours on a particular colour wheel.

Complementary colours

They are the most different possible from each other, they are opposite one
another in the colour wheel.

For example, green (resulting from the mixing the primary colours yellow and
blue [cyan]) is complementary to red. Orange (a mixture of yellow and red
[magenta]) is complementary to blue, while violet (a mixture of blue [cyan] and
red [magenta] is complementary to yellow.

Warm and cool (or cold) colours



                                                                                 22
Reds, oranges, and yellows are considered warm colours. But if you compare
different reds, oranges, or yellows (or even the colours considered cool, such as
blues), you'll see that there are also warm and cool versions of each of these
colours (relative to each other only).

Blues, greens, and purples are considered cool colours. In an aerial perspective
cool colours are said to move away from you, or appear more distant.

If you compare different blues (or greens or purples), you'll see that there are
also warm and cool versions of each of these colours, relative to each other.

Saturated or bright colours

Pure hues containing, theoretically, no white, black, grey or complementary
colours. However, this definition can be stretched to extend the range of
complementary colours. For example, the range of saturated blues is not limited
to pure blues. Blues containing white or black may still be considered saturated.
On the other hand, orange containing black, even in small quantities, is
considered unsaturated because it becomes brownish.

Pale or clear colours

Hues containing more or less white.

Dark colours

Hues containing more or less black.

Harmony

Harmony refers to a combination of colours that is pleasing to the eye.


High key and Low key images

High-key lighting is a style of lighting for film, television, or photography that
aims to reduce the lighting ratio present in the scene. This was originally done
partly for technological reasons, since early film and television did not deal well
with high contrast ratios, but now it is used to suggest an upbeat mood. It is
often used in sitcoms and comedies. High-key lighting is usually quite
homogeneous and free from dark shadows.

So what is high key? High Key images are those where contrast and shadows
are supressed, while the levels of exposure and brightness are high.

Opposing High Key images are Low Key Images. In Low Key images the tone
is darker, and the controlling colour is usually black. There will be lots of dark
areas in the picture.

Remember a terror movie, it was probably filmed in Low Key.

                                                                                23
Psychology of colour

Colour has always been important - from natural warnings in primitive times to
mood enhancers in modern homes.

Ever since man understood fiery red meant danger and that those purple
berries were poisonous, colour has been associated with moods and feelings.

Religious artists used colour as a form of shorthand - people looking at a
stained glass window or a heraldic coat of arms would have instantly known that
blue equalled contemplative faith or green meant hope. Even Saints were
associated with different colours.

White

White projects purity, cleanliness, and neutrality. Doctors don white coats,
brides traditionally wear white gowns and a white picket fence surrounds a safe
and happy home.

Red

Associated with: danger, passion, energy, warmth, adventure, optimism

Pink

Associated with: love.

Orange

Associated with: youth, joyfulness, dynamism.

Green

Associated with: nature and energy, calming and restful, balance (halfway
between red and blue) security, stability.

Blue

Associated with: calming and soothing; promotes intellectual thought, loyalty,
serenity, authority, protection, contemplative.

Yellow

Associated with: sunshine and energy, stimulates the intellect.




                                                                            24
Lilac

Associated with: spiritual matters - suggests the misty area between the sky
and heaven, feminine

Purple

Associated with: creativity, fertility, joy, but also magic, evil, death and sex

Brown

Associated with: security, stability and very practical

Black

Black is authoritative and powerful, and also represents death, eccentricity,
drama.

Gray

Gray is timeless, practical, and solid. Gray can mix well with any colour.
Although well liked and often worn, people rarely name gray as a favorite colour
possibly because gray is also associated with loss or depression.



Terms to help describe a specific shade of a colour are:

HUE

It is the quality that distinguishes one colour from another. It is, for example,
what differentiates blue from yellow.

VALUE

It refers to the position of a hue relative to the vertical grey scale. Value allows
us to qualify hues as pale or dark, or light and dark.

SATURATION OR CHROMA

It describes the horizontal spread between a hue of the same scale value as
neutral grey. Chroma allows us to describe a colour as saturated or
unsaturated, or as bright or grey-tinted. Adding grey makes the hue less
saturated or more unsaturated. A hue can also be modified with the addition of
some of its complementary colour.

TEMPERATURE—the relative warmth or coolness of a colour. Blues, greens,
and purples, or colours containing blue, green, or purple undertones are cool
colours. Reds, oranges, and yellows, or colours containing red, orange, or
yellow undertones are warm colours.

                                                                                   25
Let’s investigate on the web!

   1. Look for these items to make an essay about colour theories.

   2. Check http://en.wikipedia.org/wiki/Color_symbolism and discuss it in
groups.

   3. Make a PowerPoint presentation about the subject. (In pairs)

Optics of       Colour           Absorption        Reflection    Photoreceptors,
colour          psychology                                       Rod & cone
                                                                 cells
Isaac           Goethe           Schopenhauer Thomas             James Clerck
Newton                                          Young            Maxwell
Heinrich        Colour           Albert Munsell Hickethier’s     Paul Klee
Hetz            wheels                          cube


Let´s paint!

A. Choose a fairy tale and illustrate it in four ways:

        First, using cold colours.
        Second, using warm colours.
        Third, with High Key colours and low contrast.
        Fourth, with high contrast and a Low Key range of colours.


B. Paint a colour wheel.

C. Choose two different feelings, then try to represent them using different
colours to illuminate a landscape.




Let’s photograph!

Take some photos. (You can apply your knowledge of composition and shot
types)

With GIMP or Photoshop, change their values to obtain:

   1.   High Key images.
   2.   Low Key images.
   3.   Cold images.
   4.   Warm images.

Order and name these images into a PowerPoint presentation.

                                                                               26

				
DOCUMENT INFO
Shared By:
Categories:
Stats:
views:46
posted:2/19/2010
language:English
pages:7