<s>
Stereo	B-Algorithm
photography	I-Algorithm
techniques	I-Algorithm
are	O
methods	O
to	O
produce	O
stereoscopic	B-Algorithm
images	I-Algorithm
,	O
videos	O
and	O
films	O
.	O
</s>
<s>
This	O
is	O
done	O
with	O
a	O
variety	O
of	O
equipment	O
including	O
special	O
built	O
stereo	B-Algorithm
cameras	I-Algorithm
,	O
single	O
cameras	O
with	O
or	O
without	O
special	O
attachments	O
,	O
and	O
paired	O
cameras	O
.	O
</s>
<s>
It	O
is	O
necessary	O
to	O
take	O
two	O
photographs	O
from	O
different	O
horizontal	O
positions	O
to	O
get	O
a	O
true	O
stereoscopic	B-Algorithm
image	I-Algorithm
pair	O
.	O
</s>
<s>
This	O
can	O
be	O
done	O
with	O
two	O
separate	O
side-by-side	O
cameras	O
;	O
with	O
one	O
camera	O
moved	O
from	O
one	O
position	O
to	O
another	O
between	O
exposures	O
;	O
with	O
one	O
camera	O
and	O
a	O
single	O
exposure	O
by	O
means	O
of	O
an	O
attached	O
mirror	O
or	O
prism	O
arrangement	O
that	O
presents	O
a	O
stereoscopic	B-Algorithm
image	I-Algorithm
pair	O
to	O
the	O
camera	O
lens	O
;	O
or	O
with	O
a	O
stereo	B-Algorithm
camera	I-Algorithm
incorporating	O
two	O
or	O
more	O
side-by-side	O
lenses	O
.	O
</s>
<s>
The	O
invention	O
of	O
photography	O
in	O
1839	O
opened	O
up	O
a	O
new	O
and	O
more	O
detailed	O
medium	O
for	O
his	O
experiments	O
and	O
the	O
first	O
photographic	O
stereoscopic	B-Algorithm
pairs	O
appeared	O
in	O
the	O
early	O
1840s	O
as	O
Daguerreotypes	O
and	O
Calotypes	O
.	O
</s>
<s>
In	O
the	O
1890s	O
,	O
photographic	B-Algorithm
plates	I-Algorithm
and	O
films	O
sensitive	O
enough	O
to	O
make	O
casual	O
"	O
snapshot	O
"	O
photography	O
practical	O
were	O
available	O
,	O
and	O
combined	O
with	O
easy-to-use	O
cameras	O
they	O
were	O
making	O
amateur	O
photography	O
a	O
very	O
popular	O
hobby	O
.	O
</s>
<s>
Stereo	B-Algorithm
cameras	I-Algorithm
were	O
in	O
the	O
mix	O
.	O
</s>
<s>
The	O
popularity	O
of	O
stereo	B-Algorithm
photography	I-Algorithm
declined	O
after	O
the	O
First	O
World	O
War	O
and	O
plummeted	O
during	O
the	O
Great	O
Depression	O
of	O
the	O
1930s	O
.	O
</s>
<s>
In	O
the	O
late	O
1940s	O
,	O
compact	O
imported	O
European	O
stereo	B-Algorithm
cameras	I-Algorithm
that	O
used	O
35mm	O
slide	O
film	O
began	O
appearing	O
in	O
the	O
US	O
market	O
.	O
</s>
<s>
In	O
1945	O
,	O
ads	O
began	O
appearing	O
for	O
an	O
American	O
camera	O
known	O
as	O
the	O
Stereo	B-Algorithm
Realist	I-Algorithm
.	O
</s>
<s>
The	O
camera	O
was	O
not	O
actually	O
available	O
for	O
purchase	O
until	O
1947	O
,	O
but	O
the	O
ads	O
generated	O
a	O
lot	O
of	O
excitement	O
among	O
stereo	B-Algorithm
photography	I-Algorithm
enthusiasts	O
.	O
</s>
<s>
The	O
Stereo	B-Algorithm
Realist	I-Algorithm
featured	O
a	O
more	O
compact	O
5P	O
format	O
,	O
which	O
soon	O
became	O
known	O
as	O
the	O
"	O
Realist	O
format	O
"	O
.	O
</s>
<s>
With	O
only	O
these	O
two	O
items	O
the	O
owner	O
could	O
capture	O
,	O
relive	O
and	O
share	O
multicolored	O
and	O
stereoscopically	B-Algorithm
preserved	O
memories	O
.	O
</s>
<s>
For	O
group	O
viewing	O
,	O
a	O
polarized	O
stereoscopic	B-Algorithm
slide	O
projector	O
,	O
silver	O
screen	O
and	O
polarized	O
glasses	O
could	O
be	O
added	O
to	O
the	O
system	O
.	O
</s>
<s>
The	O
popularity	O
of	O
amateur	O
stereoscopic	B-Algorithm
photography	I-Algorithm
helped	O
trigger	O
a	O
brief	O
pop	O
culture	O
fad	O
of	O
3D	B-Algorithm
movies	I-Algorithm
,	O
3D	O
comic	O
books	O
,	O
etc.	O
,	O
which	O
in	O
turn	O
helped	O
to	O
introduce	O
new	O
enthusiasts	O
to	O
the	O
ranks	O
of	O
amateur	O
stereo	O
photographers	O
.	O
</s>
<s>
Unlike	O
the	O
pop	O
culture	O
3D	O
fad	O
,	O
which	O
came	O
and	O
went	O
quickly	O
and	O
was	O
primarily	O
a	O
1953	O
phenomenon	O
,	O
the	O
popularity	O
of	O
amateur	O
stereo	B-Algorithm
photography	I-Algorithm
started	O
earlier	O
,	O
grew	O
more	O
slowly	O
,	O
peaked	O
later	O
,	O
and	O
declined	O
more	O
gradually	O
.	O
</s>
<s>
Eight	O
new	O
stereo	B-Algorithm
cameras	I-Algorithm
hit	O
the	O
market	O
in	O
1954	O
,	O
including	O
the	O
Kodak	B-Algorithm
Stereo	I-Algorithm
Camera	I-Algorithm
which	O
may	O
have	O
driven	O
several	O
competitors	O
out	O
of	O
the	O
business	O
.	O
</s>
<s>
Kodak	O
's	O
stereo	B-Algorithm
camera	I-Algorithm
was	O
not	O
discontinued	O
until	O
1959	O
,	O
Kodaslide	O
stereo	O
viewers	O
were	O
available	O
until	O
1962	O
,	O
and	O
the	O
Realist	O
continued	O
in	O
production	O
,	O
although	O
ultimately	O
in	O
very	O
small	O
quantities	O
,	O
into	O
1971	O
.	O
</s>
<s>
The	O
1980s	O
saw	O
a	O
minor	O
revival	O
of	O
stereoscopic	B-Algorithm
photography	I-Algorithm
when	O
several	O
point-and-shoot	O
stereo	B-Algorithm
cameras	I-Algorithm
were	O
introduced	O
.	O
</s>
<s>
Most	O
of	O
these	O
cameras	O
suffered	O
from	O
poor	O
optics	O
and	O
plastic	O
construction	O
and	O
were	O
designed	O
to	O
produce	O
lenticular	O
prints	O
,	O
a	O
format	O
which	O
never	O
gained	O
wide	O
acceptance	O
,	O
so	O
they	O
never	O
gained	O
the	O
popularity	O
of	O
the	O
1950s	O
stereo	B-Algorithm
cameras	I-Algorithm
.	O
</s>
<s>
Stereo	O
lenses	O
were	O
introduced	O
which	O
could	O
turn	O
an	O
ordinary	O
film	O
camera	O
into	O
a	O
stereo	B-Algorithm
camera	I-Algorithm
by	O
using	O
a	O
special	O
double	O
lens	O
to	O
take	O
two	O
images	O
and	O
direct	O
them	O
through	O
a	O
single	O
lens	O
to	O
capture	O
them	O
side	O
by	O
side	O
on	O
the	O
film	O
.	O
</s>
<s>
In	O
2009	O
digital	O
stereo	B-Algorithm
cameras	I-Algorithm
such	O
as	O
the	O
Fuji	O
W1	O
began	O
appearing	O
in	O
the	O
consumer	O
market	O
.	O
</s>
<s>
Several	O
companies	O
joined	O
the	O
digital	O
stereo	O
market	O
producing	O
digital	O
stereo	B-Algorithm
cameras	I-Algorithm
that	O
sold	O
for	O
as	O
little	O
as	O
$100	O
.	O
</s>
<s>
Newer	O
cameras	O
,	O
such	O
as	O
the	O
Fuji	O
W3	O
,	O
can	O
also	O
be	O
used	O
to	O
shoot	O
full	O
motion	O
480P	O
video	O
at	O
up	O
30	O
frames	O
per	O
second	O
or	O
720P	O
video	O
at	O
24	O
frames	O
per	O
second	O
,	O
thus	O
making	O
amateur	O
3D	B-Algorithm
video	I-Algorithm
possible	O
.	O
</s>
<s>
For	O
general	O
purpose	O
stereo	B-Algorithm
photography	I-Algorithm
,	O
where	O
the	O
goal	O
is	O
to	O
duplicate	O
natural	O
human	O
vision	O
and	O
give	O
a	O
visual	O
impression	O
as	O
close	O
as	O
possible	O
to	O
actually	O
being	O
there	O
,	O
the	O
correct	O
baseline	O
(	O
distance	O
between	O
where	O
the	O
right	O
and	O
left	O
images	O
are	O
taken	O
)	O
would	O
be	O
the	O
same	O
as	O
the	O
distance	O
between	O
the	O
eyes	O
.	O
</s>
<s>
This	O
is	O
what	O
is	O
generally	O
referred	O
to	O
as	O
a	O
"	O
normal	O
"	O
baseline	O
,	O
used	O
in	O
most	O
stereo	B-Algorithm
photography	I-Algorithm
.	O
</s>
<s>
Note	O
that	O
the	O
concept	O
of	O
baseline	O
also	O
applies	O
to	O
other	O
branches	O
of	O
stereography	B-Algorithm
,	O
such	O
as	O
stereo	O
drawings	O
and	O
computer	O
generated	O
stereo	O
images	O
,	O
but	O
it	O
involves	O
the	O
point	O
of	O
view	O
chosen	O
rather	O
than	O
actual	O
physical	O
separation	O
of	O
cameras	O
or	O
lenses	O
.	O
</s>
<s>
The	O
shift	O
method	O
has	O
been	O
used	O
with	O
cameras	O
such	O
as	O
the	O
Stereo	B-Algorithm
Realist	I-Algorithm
to	O
take	O
hypers	O
,	O
either	O
by	O
taking	O
two	O
pairs	O
and	O
selecting	O
the	O
best	O
frames	O
,	O
or	O
by	O
alternately	O
capping	O
each	O
lens	O
and	O
recocking	O
the	O
shutter	O
.	O
</s>
<s>
Similar	O
techniques	O
were	O
used	O
late	O
in	O
the	O
19th	O
century	O
to	O
take	O
stereo	O
views	O
of	O
Mars	B-Application
and	O
other	O
astronomical	O
subjects	O
.	O
</s>
<s>
If	O
a	O
picture	O
is	O
taken	O
with	O
a	O
stereo	B-Algorithm
camera	I-Algorithm
(	O
or	O
pair	O
of	O
cameras	O
)	O
and	O
a	O
4X	O
telephoto	O
lens	O
or	O
4X	O
zoom	O
built	O
into	O
the	O
camera(s )	O
is	O
used	O
,	O
objects	O
will	O
be	O
the	O
size	O
they	O
would	O
be	O
at	O
1/4	O
the	O
distance	O
,	O
but	O
will	O
have	O
no	O
where	O
near	O
the	O
depth	O
,	O
which	O
is	O
why	O
zoom	O
is	O
generally	O
frowned	O
upon	O
in	O
stereo	B-Algorithm
photography	I-Algorithm
.	O
</s>
<s>
It	O
does	O
,	O
however	O
,	O
represent	O
a	O
specialized	O
branch	O
of	O
stereography	B-Algorithm
.	O
</s>
<s>
Recent	O
research	O
has	O
led	O
to	O
precise	O
methods	O
for	O
calculating	O
the	O
stereoscopic	B-Algorithm
camera	I-Algorithm
baseline	O
.	O
</s>
<s>
This	O
approach	O
means	O
there	O
is	O
no	O
guesswork	O
in	O
the	O
stereoscopic	B-Algorithm
setup	O
once	O
a	O
small	O
set	O
of	O
parameters	O
have	O
been	O
measured	O
,	O
it	O
can	O
be	O
implemented	O
for	O
photography	O
and	O
computer	O
graphics	O
and	O
the	O
methods	O
can	O
be	O
easily	O
implemented	O
in	O
a	O
software	O
tool	O
.	O
</s>
<s>
The	O
precise	O
methods	O
for	O
camera	O
control	O
have	O
also	O
allowed	O
the	O
development	O
of	O
multi-rig	O
stereoscopic	B-Algorithm
cameras	I-Algorithm
where	O
different	O
slices	O
of	O
scene	O
depth	O
are	O
captured	O
using	O
different	O
inter-axial	O
settings	O
,	O
the	O
images	O
of	O
the	O
slices	O
are	O
then	O
composed	O
together	O
to	O
form	O
the	O
final	O
stereoscopic	B-Algorithm
image	I-Algorithm
pair	O
.	O
</s>
<s>
This	O
allows	O
important	O
regions	O
of	O
a	O
scene	O
to	O
be	O
given	O
better	O
stereoscopic	B-Algorithm
representation	O
while	O
less	O
important	O
regions	O
are	O
assigned	O
less	O
of	O
the	O
depth	O
budget	O
.	O
</s>
