<s>
A	O
3D	B-Algorithm
rig	I-Algorithm
is	O
a	O
device	O
for	O
mounting	O
two	O
cameras	O
together	O
to	O
one	O
3D-system	O
in	O
order	O
to	O
shoot	O
stereoscopic	B-Algorithm
films	O
and	O
images	O
.	O
</s>
<s>
To	O
create	O
stereoscopic	B-Algorithm
depth	O
illusion	O
in	O
movie	O
or	O
photography	O
,	O
two	O
slightly	O
different	O
images	O
have	O
to	O
be	O
viewed	O
at	O
the	O
same	O
time	O
,	O
each	O
of	O
them	O
presented	O
to	O
one	O
eye	O
.	O
</s>
<s>
In	O
addition	O
to	O
that	O
the	O
cameras	O
have	O
to	O
be	O
geometrically	O
aligned	O
accurately	O
,	O
to	O
minimize	O
the	O
amount	O
of	O
stereoscopic	B-Algorithm
errors	O
.	O
</s>
<s>
A	O
3D	B-Algorithm
Rig	I-Algorithm
,	O
as	O
a	O
result	O
,	O
must	O
provide	O
the	O
possibility	O
to	O
mount	O
two	O
cameras	O
,	O
with	O
a	O
horizontal	O
offset	O
and	O
adjust	O
the	O
cameras	O
in	O
all	O
possible	O
axes	O
.	O
</s>
<s>
In	O
general	O
there	O
are	O
two	O
types	O
of	O
3D	B-Algorithm
Rigs	I-Algorithm
,	O
side-by-side	O
rigs	O
and	O
mirror	O
rigs	O
.	O
</s>
<s>
Another	O
advantage	O
is	O
,	O
that	O
the	O
images	O
can	O
be	O
used	O
for	O
the	O
geometrical	O
alignment	O
of	O
the	O
cameras	O
since	O
stereoscopic	B-Algorithm
errors	O
can	O
be	O
seen	O
most	O
easily	O
when	O
the	O
interaxial	O
distance	O
is	O
zero	O
.	O
</s>
