<s>
A	O
polarized	B-Algorithm
3D	I-Algorithm
system	I-Algorithm
uses	O
polarization	O
glasses	O
to	O
create	O
the	O
illusion	O
of	O
three-dimensional	O
images	O
by	O
restricting	O
the	O
light	O
that	O
reaches	O
each	O
eye	O
(	O
an	O
example	O
of	O
stereoscopy	B-Algorithm
)	O
.	O
</s>
<s>
To	O
present	O
stereoscopic	B-Algorithm
images	I-Algorithm
and	O
films	O
,	O
two	O
images	O
are	O
projected	O
superimposed	O
onto	O
the	O
same	O
screen	O
or	O
display	O
through	O
different	O
polarizing	O
filters	O
.	O
</s>
<s>
Multiple	O
people	O
can	O
view	O
the	O
stereoscopic	B-Algorithm
images	I-Algorithm
at	O
the	O
same	O
time	O
.	O
</s>
<s>
Polarized	B-Algorithm
3D	I-Algorithm
systems	I-Algorithm
,	O
and	O
stereoscopy	B-Algorithm
systems	O
in	O
general	O
,	O
commonly	O
exhibit	O
the	O
Vergence-Accommodation	O
Conflict	O
.	O
</s>
<s>
To	O
present	O
a	O
stereoscopic	B-Algorithm
motion	O
picture	O
,	O
two	O
images	O
are	O
projected	O
superimposed	O
onto	O
the	O
same	O
screen	O
through	O
orthogonal	O
polarizing	O
filters	O
(	O
Usually	O
at	O
45	O
and	O
135	O
degrees	O
)	O
.	O
</s>
<s>
Linearly	O
polarised	B-Algorithm
glasses	I-Algorithm
require	O
the	O
viewer	O
to	O
keep	O
his	O
or	O
her	O
head	O
level	O
,	O
as	O
tilting	O
of	O
the	O
viewing	O
filters	O
will	O
cause	O
the	O
images	O
of	O
the	O
left	O
and	O
right	O
channels	O
to	O
bleed	O
over	O
to	O
the	O
opposite	O
channel	O
.	O
</s>
<s>
To	O
present	O
a	O
stereoscopic	B-Algorithm
motion	O
picture	O
,	O
two	O
images	O
are	O
projected	O
superimposed	O
onto	O
the	O
same	O
screen	O
through	O
circular	O
polarizing	O
filters	O
of	O
opposite	O
handedness	O
.	O
</s>
<s>
The	O
result	O
is	O
similar	O
to	O
that	O
of	O
stereoscopic	B-Algorithm
viewing	O
using	O
linearly	O
polarized	O
glasses	O
,	O
except	O
the	O
viewer	O
can	O
tilt	O
his	O
or	O
her	O
head	O
and	O
still	O
maintain	O
left/right	O
separation	O
(	O
although	O
stereoscopic	B-Algorithm
image	I-Algorithm
fusion	O
will	O
be	O
lost	O
due	O
to	O
the	O
mismatch	O
between	O
the	O
eye	O
plane	O
and	O
the	O
original	O
camera	O
plane	O
)	O
.	O
</s>
<s>
Polarized	O
light	O
reflected	O
from	O
an	O
ordinary	O
motion	O
picture	O
screen	O
typically	O
loses	O
most	O
of	O
its	O
polarization	O
,	O
but	O
the	O
loss	O
is	O
negligible	O
if	O
a	O
silver	O
screen	O
or	O
aluminized	B-General_Concept
screen	I-General_Concept
is	O
used	O
.	O
</s>
<s>
This	O
means	O
that	O
a	O
pair	O
of	O
aligned	O
DLP	B-General_Concept
projectors	I-General_Concept
,	O
some	O
polarizing	O
filters	O
,	O
a	O
silver	O
screen	O
,	O
and	O
a	O
computer	O
with	O
a	O
dual-head	O
graphics	O
card	O
can	O
be	O
used	O
to	O
form	O
a	O
relatively	O
high-cost	O
(	O
over	O
US$	O
10,000	O
in	O
2010	O
)	O
system	O
for	O
displaying	O
stereoscopic	B-Algorithm
3D	I-Algorithm
data	O
simultaneously	O
to	O
a	O
group	O
of	O
people	O
wearing	O
polarized	O
glasses	O
.	O
</s>
<s>
In	O
the	O
case	O
of	O
RealD	B-Algorithm
3D	I-Algorithm
a	O
circularly	O
polarizing	O
liquid	B-Device
crystal	I-Device
filter	O
which	O
can	O
switch	O
polarity	O
144	O
times	O
per	O
second	O
is	O
placed	O
in	O
front	O
of	O
the	O
projector	O
lens	O
.	O
</s>
<s>
Sony	O
features	O
a	O
new	O
system	O
called	O
RealD	B-Algorithm
XLS	I-Algorithm
,	O
which	O
shows	O
both	O
circularly	O
polarized	O
images	O
simultaneously	O
:	O
A	O
single	O
4K	O
projector	O
displays	O
two	O
2K	O
images	O
one	O
above	O
the	O
other	O
,	O
a	O
special	O
lens	O
attachment	O
polarizes	O
and	O
projects	O
the	O
images	O
on	O
top	O
of	O
each	O
other	O
.	O
</s>
<s>
Polarizing	O
techniques	O
are	O
easier	O
to	O
apply	O
with	O
cathode	B-Device
ray	I-Device
tube	I-Device
(	O
CRT	O
)	O
technology	O
than	O
with	O
Liquid	B-Device
crystal	I-Device
display	I-Device
(	O
LCD	B-Device
)	O
.	O
</s>
<s>
Ordinary	O
LCD	B-Device
screens	I-Device
already	O
contain	O
polarizers	O
for	O
control	O
of	O
pixel	O
presentation	O
—	O
this	O
can	O
interfere	O
with	O
these	O
techniques	O
.	O
</s>
<s>
In	O
optometry	O
and	O
ophthalmology	O
,	O
polarized	O
glasses	O
are	O
used	O
for	O
various	O
tests	O
of	O
binocular	B-Algorithm
depth	I-Algorithm
perception	I-Algorithm
(	O
i.e.	O
</s>
<s>
stereopsis	B-Algorithm
)	O
.	O
</s>
<s>
Imaginatively	O
colorized	O
versions	O
have	O
helped	O
to	O
spread	O
the	O
myth	O
that	O
the	O
3-D	O
movies	O
of	O
the	O
1950s	O
were	O
projected	O
by	O
the	O
anaglyph	B-Algorithm
color	I-Algorithm
filter	I-Algorithm
method	O
.	O
</s>
<s>
In	O
the	O
2000s	O
,	O
computer	O
animation	O
,	O
digital	O
projection	O
,	O
and	O
the	O
use	O
of	O
sophisticated	O
IMAX	O
70mm	O
film	O
projectors	O
,	O
have	O
created	O
an	O
opportunity	O
for	O
a	O
new	O
wave	O
of	O
polarized	B-Algorithm
3D	I-Algorithm
films	O
.	O
</s>
<s>
In	O
the	O
2000s	O
,	O
RealD	B-Algorithm
Cinema	I-Algorithm
and	O
MasterImage	B-Algorithm
3D	I-Algorithm
were	O
introduced	O
,	O
both	O
using	O
circular	O
polarization	O
.	O
</s>
<s>
At	O
IBC	O
2011	O
in	O
Amsterdam	O
RAI	O
several	O
companies	O
,	O
including	O
Sony	O
,	O
Panasonic	O
,	O
JVC	O
&	O
others	O
highlighted	O
their	O
upcoming	O
3D	O
stereoscopic	B-Algorithm
product	O
portfolios	O
for	O
both	O
the	O
professional	O
and	O
consumer	O
markets	O
to	O
use	O
the	O
same	O
polarization	O
technique	O
as	O
RealD	B-Algorithm
3D	I-Algorithm
Cinema	O
uses	O
for	O
stereoscopy	B-Algorithm
.	O
</s>
<s>
Their	O
systems	O
are	O
interoperable	O
and	O
compatible	O
with	O
existing	O
,	O
passive	O
RealD	B-Algorithm
3D	I-Algorithm
glasses	O
.	O
</s>
<s>
Compared	O
to	O
anaglyph	B-Algorithm
images	I-Algorithm
,	O
the	O
use	O
of	O
polarized	B-Algorithm
3D	I-Algorithm
glasses	I-Algorithm
produces	O
a	O
full-color	O
image	O
that	O
is	O
considerably	O
more	O
comfortable	O
to	O
watch	O
and	O
is	O
not	O
subject	O
to	O
binocular	B-Algorithm
rivalry	O
.	O
</s>
<s>
However	O
,	O
it	O
requires	O
a	O
significant	O
increase	O
in	O
expense	O
:	O
even	O
the	O
low	O
cost	O
polarized	O
glasses	O
typically	O
cost	O
50%	O
more	O
than	O
comparable	O
red-cyan	O
filters	O
,	O
and	O
while	O
anaglyph	B-Algorithm
3-D	I-Algorithm
films	O
can	O
be	O
printed	O
on	O
one	O
line	O
of	O
film	O
,	O
a	O
polarized	O
film	O
was	O
often	O
done	O
with	O
a	O
special	O
set	O
up	O
that	O
uses	O
two	O
projectors	O
.	O
</s>
<s>
Until	O
2011	O
,	O
home	O
3D	B-Algorithm
television	I-Algorithm
and	O
home	O
3D	O
computer	O
primarily	O
used	O
active	B-Algorithm
shutter	I-Algorithm
glasses	I-Algorithm
with	O
LCD	B-Device
or	O
plasma	O
displays	O
.	O
</s>
