The Camera

Chapter 4

VOCABULARY

• APERTURE: Iris opening of a lens• BEAM SPLITTER: optical device within the

camera that splits white light into 3 primary colors: Red, Green & Blue

• CAMCORDER: a portable camera with a VTR (video tape recorder) built-in

• CCD (charge-coupled device, also called chip): an image-sensing element that translates the optical or light image into a video signal

VOCABULARY

• FOCAL LENGTH: With the lens set at infinity, the distance from the iris to the plane where the picture is in focus

• IRIS: Adjustable lens-opening mechanism• VIEWFINDER: A small video monitor on a

camera that displays the picture the camera generates

• ZOOM LENS: Variable-focal-length lens, all cameras are equipped with a zoom lens

Basic Functions

• Every camera needs 3 basic elements:– The lens– The camera, itself– The viewfinder

• The lens captures the visual or optical image• The camera converts the image into an

electrical video signal.• The viewfinder reconverts the electrical video

signal into a video picture.

• Turn to page 48 and let’s discuss image 4.1 and 4.2.

• Lenses come in different sizes.– A wide-angle lens shows a wide vista (faraway

objects look small)– A narrow-angle lens shows a narrow vista, with

faraway objects looking greatly magnified.• The zoom lens on a camera changes the focal

length.– A short focal length gives you a wide-angle view.– A long focal length gives you a narrow angle view.

• The zoom range is the measurement from the farthest position to the closest position.– Optical zoom: occurs inside the lens– Digital zoom: starting at the center of the object

and magnifying it.• Pixels:

• Iris: controls the amount of light transmitted through the camera. Many cameras have an automatic iris.– Just like the focus ring is measured, so is the iris

ring.• Turn to page 52 and let’s discuss image 4.8– Create your own telescope lens

• The beam splitter uses prisms and filters to split the white light into Red, Green or Blue. The splits create electric energy sent to the CCD.

• The CCD (charge-coupled device) translates the light energy into an electric charge, creating a video signal.– High quality cameras have 3 CCD’s, one for each

primary color.– Most consumer cameras have 1 CCD.

• Many viewfinders today are small, rotating LCD (liquid crystal display) screens.– Are all viewfinders displayed in color?– Why or why not?

Quiz

• 1. What are the 3 basic elements each video camera needs to function?

• 2. The beam splitter is an optical device within the camera that splits white light into 3 primary colors. What are the 3 colors?

• 3. All video cameras operate on the same basic principle: to translate the optical image that the lens sees into a corresponding video picture. In your own words, summarize how this happens.

Types of Cameras

• Studio Cameras- large, heavy, high quality, and usually moved on a pedestal with wheels– What are some characteristics that make them high

quality?– Turn to page 56 and let’s discuss image 4.12– Turn to page 57 and let’s discuss images 4.13 & 4.14

• Field Cameras- the difference between a studio and field camera is usually the lens. – Higher zoom ratio. Why?– Mounted on tripods. Why?

• What is an ENG camera?• What is an EFP camera?• What are the differences?

• What differentiates a camcorder from a camera?

• What are some traits of a consumer camcorder?– Lens: zoom range, smother zoom movements,

wider aperture– Microphone: built-in and jacks– CCD: color and light– Synchronization: multiple use