Transcript Principles of Light PowerPoint

Principles of Light
The Science Behind Photography
1. White light is
made up of equal
amounts of red,
blue and green
light.
additive process
subtractive process
1. White light is made up of equal
amounts of red, blue and green light.
• Red, Blue and Green
RED
• Cannot be made
WHITE
BLUE
GREEN
• Exist in Nature
• PRIMARY COLORS
1. White light is made up of equal
amounts of red, blue and green light.
RED
MAGENTA
YELLOW
WHITE
BLUE
GREEN
CYAN
1. White light is made up of equal
amounts of red, blue and green light.
MAGENTA
• Cyan, Magenta, Yellow
RED
YELLOW
WHITE
BLUE
GREEN
• Combine EQUAL amounts
of 2 PRIMARY colors
• SECONDARY COLORS
CYAN
1. White light is made up of equal
amounts of red, blue and green light.
•
•
Wavelengths of color are viewed on the spectrum.
Visible Spectrum = Rainbow
Water acts like a PRISM to REFRACT or BREAK APART white light into all colors
1. White light is made up of equal amounts of red, blue and green light.
1. White light is made up of equal
amounts of red, blue and green light.
1. White light is made up of equal
amounts of red, blue and green light.
• All colored objects reflect light to
some degree.
• White objects reflect all the light that
hits them.
• Can only take a photograph when
there is a light source.
• No light = No color
2. Objects get their color
from reflected light.
2. Objects get their color from reflected light.
Can you change the color of
an object by changing the
light source?
2. Objects get their color from reflected light.
You can change the color of
an object by changing the
light source!
2. Objects get their color from reflected light.
• Black is not a color
• It is the absence of color
• Black objects absorb ALL the light
that hits them
• Inside if cameras, darkroom,
developing tanks are black
• WHY?
3. Black objects absorb all light.
Can you see this?
Can a camera see black?
Can black be photographed?
Will the film be exposed?
3. Black objects absorb all light.
Camera cannot see black?
Black cannot be photographed?
The film will not be exposed?
3. Black objects absorb all light.
• Silver is the main ingredient in film/
photo paper because it is sensitive to
light.
• Silverware and jewelry tarnishes.
4. Silver, when struck by
light, turns black.
• Film/photo paper has two main layers:
• Emulsion
• Emulsion
– silver particles
• Base
suspended in a gel
• Base – support for the
emulsion; paper or plastic
4. Silver, when struck by
light, turns black.
• Emulsion – silver particles suspended in a gel
• Base – support for the emulsion; paper or plastic
EMULSION
BASE
4. Silver, when struck by
light, turns black.
EMULSION
BASE
4. Silver, when struck by
light, turns black.
• Light travels in wavelengths.
5. Light travels in a
straight path.
5. Light travels in a
straight path.
• Images are recorded on film upside
down and reversed.
• We see the same way.
5. Light travels in a
straight path.
5. Light travels in a
straight path.
5. Light travels in a straight path.
• Larger lens opening, more light,
blurry image
• Smaller lens opening, less light,
sharper image
5. Light travels in a straight path.
http://youtu.be/O0PawPSdk28