Camera Film and HDContinued

Basics (review) • Like an imperfect eye• Lens gathers light reflected off surfaces• A surface senses the pattern formed by differences in

brightness and color• In the case of the eye patterns of light are interpreted by the

eye

Lens and Camera• Both images are upside down• Because the eye and lenses are

convex (curve outward)• Always invert images• In the brain (or in the camera

viewfinder, the images are turned right side up)

• Work the same as still cameras • Record multiple frames per

second

HD cameras

Exposure • The amount of light that comes through the lens• The hole in the lens is called the aperture• Large apertures let in lots of light• Small apertures let in less light• An f/stop is a measure of how big or little the aperture is• Aperture numbers are fractions• F/2 means the aperture is ½ as big across as the lens is long• F/16 means that the aperture is 1/16 as big across as the lens

is long

F-stops• Each stop down admits ½

as much light as one before

• F/4 admits half as much light as F/2.8

Black and White vs Color

• BW Light sensitive emulsion and plastic base• Color Plastic base with 3 emulsion layers: Red, Green and Blue

Film Stocks • Faster Film (higher number—200 as ex. Can shoot in lower

light) • Slower Film (lower number—needs more light)

Color Temperature• Light comes in different colors

ISO• abbreviation• International Organization for Standardization.• Formerly ASA (American Standards Organization)

CCD Chips• Can only handle one color of light

source at a time• Color temperature color filters• Color temperature is a way to identify

different colors of light sources• Measured in degrees Kelvin• Lord Kelvin devised the system• Like 2500k• Coal: 2000k is the reddish light

produced at 2000 degrees Kelvin and 8000k is the bluish light produced by 8000 degrees Kelvin

• Color filters are used to convert the existing light to the color temperature required

HD Cameras • Built in filters• Set according to the

light you’ll be shooting under

• Tungsten 3200k• Mixed (Fluorescent)

4300k• Daylight 5400k• Shade 6000k

Tungsten vs Daylight • White light is made up of three primary colors• Eyes adjust • Every light has a color temperature• (Kelvin discovered that heating a block of carbon changed its

color) • His system does not relate directly to actual temperature• Lower temps are warmer and Higher temps are bluer

Daylight vs Tungsten Balanced Film

LightIs made up of three different colors

RGBA tungsten bulb and sunlight both look white to our eyes

Film and video chips are more sensitive to different light sources

Every light source has a temperature measured in degrees Kelvin

Different types of color film

500T Film “Tungsten Film”50D Film “Daylight Film”

85 orange (Filter)80a Blue (Filter)

Filters absorb light at different rates and this is called the filter factor

White Balance