Childrens Illustrated Encyclopedia

Movie caMeras

The movement we see

in a movie theater is an

illusion. A movie (cinema)

film is really a series of still

pictures projected onto

the screen in such quick

succession that they

seem to merge into one

another. If the subject is in

a slightly different place

in each picture, it looks as if it is moving. Most movie

cameras take 24 pictures, or frames, every second.

Until recently, these frames were captured on a very

long strip of film wound steadily through the camera.

Now, most filmmakers use digital cameras instead.

KINds of cAMerAs

There are many different types of cameras, including

film, digital, compact, single-lens reflex, disposable,

instant-picture, and large-format cameras. However,

film usage has dropped

so dramatically that many

manufacturers have

stopped making it.

Today, tiny digital

cameras are also built

into most mobile

phone handsets.

AlTHoUgH THe fIrsT pHoTogrApH was taken

only about 190 years ago, cameras are much, much

older. Hundreds of years ago, the chinese found that

light entering a dark room through a pinhole would

project a fuzzy image of the world outside on to the

opposite wall. Many years later, in 1500 in europe, a

room like this was called a camera obscura, which is

latin for “darkened room”. In the 17th century, some

artists drew sketches with the aid of a camera obscura,

which had a lens instead of a pinhole to make the

image sharper and brighter. The discovery of chemicals

that darkened when exposed to light finally made it

possible to fix the image permanently—on paper, on

glass plates, or on film. Today, digital cameras use light-

sensitive electronic sensors instead of film. sophisticated

electronic technology in most cameras ensures

that each picture gets the right amount of light

(autoexposure) and is perfectly sharp (autofocus).

But all cameras still work on the same basic principle

as the camera obscura of old.

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lArge-forMAT cAMerA

In early cameras, the lens was

focused by moving a bellows—an

accordian-like cloth tunnel—in

and out. Many photographers still

use large-format bellows cameras for

high-quality studio work.

Cameras

Find out more

light

Movies

photography

Telescopes

Television

polAroId cAMerA

The polaroid “instant-picture”

camera took just 90 seconds to

process a picture. Today, however,

they have been replaced by instant

digital techniques, like

portable printers.

dIgITAl cAMerA

A digital camera captures images

electronically rather than on standard

film and stores them on removable

memory cards. Images can then

be transferred to a computer and

printed out or sent over the Internet.

dIgITAl

pHoTo prINTers

some digital cameras

can be connected directly to

printers in order to print out

photos, and many printers have

slots for memory cards to be

inserted. This makes transferring

images to a computer unnecessary.

sINgle-leNs reflex cAMerA

The single-lens reflex (slr) camera

(above) may use either film or a digital sensor. It is

popular with photographers for its versatility, and

because the viewfinder shows exactly the same view that

the camera will record. The lens can be interchanged

with others to give a wide view or to magnify the subject.

Photos stored on the

camera’s memory card

can be viewed on the LCD

(liquid crystal display).

Light travels from

subject to lens.

Sensor is made of millions

of pixels. Each measures

brightness and color of

one tiny part of the image.

Autofocus system

ensures sharp images.

Removable memory

card stores images.

Filter used to

enhance image

and protect lens.

Screen allows users to

check pictures instantly.

Circuit processes output

from sensor into digital form,

so it can be viewed, deleted,

or stored.

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