you've got Facebook albums full of photos.

You have photos on your computer desktop,

on your mobile phone,

on your bedroom wall.

You see photos in magazines and newspapers,

on the side of buses,

and of course, in your family albums.

We take photos for granted in a major way.

But, creating a picture

that looked exactly like the person or thing

that you were photographing wasn't always obvious.

In fact, in the past, it was a big mystery.

How could you, in essence,

take your reflection in the mirror

and freeze it in there?

In the 9th century,

the Arab scientist Alhazen

had come up with the idea

of using the camera obscura,

which was literally a dark room, or box,

with a single, small hole in one side that let light through.

This would project the image outside into the wall inside.

During the Renaissance,

artists like Leonardo DaVinci used this method

to introduce 3-D scenes onto a flat plane

so that they could copy things,

like perspective, more easily.

In 1724, Johann Heinrich Schultz discovered

that exposing certain silver compounds to light

altered their appearance

and left marks wherever the light touched.

Essentially, Schultz found a way to record the images

that Alhazen was able to project,

but only for a little while.

Schultz's images disappeared soon after he had made them.

It wasn't until 1839 that people figured out

how to project images onto light-sensitive surfaces

that would retain the image after exposure,

and thus, photography was born.

At that point, it was mostly two inventors

who fought for the best way to make photos.

One was British scientist Henry Fox Talbot,

whose calotype process used paper

and allowed many copies to be made

from a single negative.

The other inventor, Louis Daguerre,

was an artist and chemist in France.

He developed something called a daguerreotype,

which used a silvered plate

and which produced a sharper image.

But the daguerreotype could only make positive images

so copies had to be made by taking another photo.

In the end, the daguerreotype won out

as the first commercially successful photographic process

mostly because the government made it freely available to the public.

So now that photography was available,

getting a picture of yourself would be a snap, right?

Well, not exactly!

This process still required a whole dark room

at the location of the photograph,

which was a big hassle.

Picture the early photographers lugging

enormous trailers with all their equipment

wherever they wanted to take a picture.

Not only that, but the early processes

had extremely long exposure times.

To get a good photo, you would have to stand perfectly still

for up to two minutes!

This led to development of inventions like

the head holder,

a wire frame that would hide behind you

while supporting your head.

It's also why you don't see people smiling

in early photographs.

It's not that life was that bad,

it was just hard to keep a steady grin

for more than a few seconds,

so people opted for a straight-faced look.

And then George Eastman came along.

Eastman believed that everyone

should have access to photography,

and he spent many late nights

mixing chemicals in his mother's kitchen

to try to achieve a dry plate photographic process.

This would allow exposed negatives

to be stored and developed later

at a more convenient place

instead of carting those dark rooms,

necessary for wet plates, around.

After starting a business,

which initially made dry plates,

Eastman eventually discovered plastic roll film

that would fit in hand-held, inexpensive cameras.

These cameras sold by the millions under the tag line,

"You push the button,

we do the rest."

While Eastman was largely responsible

for making photography a universal past time,

even he could not have dreamed of the ways

photography had since shaped the world.

It's now estimated that over 380 billion photographs

are taken each year.

That's more photographs each day

than were taken in the first hundred years

after photography was invented.

Say cheese!