<s>
A	O
field	B-Algorithm
camera	I-Algorithm
is	O
a	O
view	B-Algorithm
camera	I-Algorithm
that	O
can	O
be	O
folded	O
in	O
a	O
compact	O
size	O
.	O
</s>
<s>
Modern	O
designs	O
are	O
little	O
different	O
from	O
the	O
first	O
folding	O
field	B-Algorithm
cameras	I-Algorithm
from	O
the	O
19th	O
century	O
.	O
</s>
<s>
In	O
general	O
they	O
have	O
more	O
limited	O
camera	O
movements	O
than	O
monorail	B-Algorithm
cameras	I-Algorithm
,	O
but	O
when	O
folded	O
are	O
relatively	O
compact	O
and	O
portable	O
.	O
</s>
<s>
Modern	O
field	B-Algorithm
cameras	I-Algorithm
originate	O
from	O
the	O
early	O
interlocking	O
box	O
cameras	O
of	O
the	O
19th	O
century	O
.	O
</s>
<s>
Although	O
they	O
have	O
less	O
flexibility	O
than	O
monorail	B-Algorithm
cameras	I-Algorithm
,	O
modern	O
field	B-Algorithm
cameras	I-Algorithm
tend	O
to	O
have	O
most	O
camera	O
movements	O
for	O
the	O
front	O
standard	O
,	O
i.e.	O
</s>
<s>
They	O
usually	O
use	O
sheet	O
film	O
,	O
in	O
sizes	O
from	O
6x9cm	O
(	O
2.4	O
×	O
3.6	O
"	O
)	O
to	O
20×24	O
inches	O
(	O
e.g.	O
,	O
the	O
Polaroid	B-Algorithm
20×24	I-Algorithm
camera	I-Algorithm
)	O
,	O
but	O
the	O
most	O
popular	O
"	O
standard	O
"	O
sizes	O
are	O
4×5	O
and	O
8×10	O
inches	O
.	O
</s>
