Ch 5 - Light Flashcards
electromagnetic energy
energy traveling along ant of the frequencies included in the electromagnetic spectrum that includes (from lowest to highest) radio, infrared, visible light, UV, x-rays, gamma rays, and cosmic rays
exposure
the result of light striking photosensitive material, such as photographic film or CCD in video camera
lumen
international unit of light emitting from light fixture
illuminance
brightness of light as it strikes surface
attenuation
weakening of energy wave as it travels
reflected light meter
type of light meter that reads intensity of light bouncing off surface (luminance)
incident light meter
reads intensity of light emitting from light source
contrast
comparison between lightest and darkest objects in frame
contrast ratio
numerically compares luminance/brightness reflected off brightest and darkest surface in frame
dynamic range
describes range of brightness and darkness that can reproduce
waveform monitors
display graphic representation of video signal
hard/direct/spotted light
light waves traveling in straight lines, producing light energy that covers limited area with max intensity; results in harsh highlights and dark, hard-edged shadows
soft/diffused/flooded light
light waves bent through or bounced off surface, producing light energy that covers broad area; results in less intense highlights and lighter, soft-edged shadows
key/fill ratio
brightness relationship between key and fill lights
kicker
light to side of and behind subject that highlights hair and gives glamorous look
wavelength
measurement of one full cycle of wave
cones
cells in retina that are sensitive to brightness and color
rods
cells in retina that are sensitive to dim light
hue
what color something is
brightness
how much light is reflected and how close to complete reflectance or absorption a color is
saturation
intensity of hue
additive color mixing
creation of color by mixing light (red, blue, green); creates white light
subtractive color mixing
system of color mixing based on cyan, magenta, and yellow primaries that form black when mixed
color temperature
specific proportion of wavelengths from across the color spectrum within any source of light, measured in kelvin
Kelvin
unit of measurement for the color temperature of light
existing light
light natural to location (ambient light)
added light
light created by instruments that are brought to a location to augment existing light
HMI lights
portable lighting instruments designed to match color temp of daylight
LED light
light-emitting diode; small component illuminated when supplied with voltage
tungsten film
balanced at 3200K, color of quartz bulb
daylight film
balanced at 5400K, average of sun’s color temp
filters
translucent, colored glass/plastic that absorb some of filter’s complementary colors, making white light close to color of filter
three-chip camera
light split into RGB with prism/beam splitter; 3 chips covered with light sensitive pixels; each chip receives one color component
beam splitter
device in video/digital still camera that separates incoming light to RGB to be received by imaging chips/tubes
chrominance
color info of light
white balancing
process in video/digital still cameras that electronically adjusts color of light entering lens so white is neutral and other colors are accurately reproduced
neutral density
grey filters/gels that decrease intensity of light without affecting color temperature
