<s>
A	O
system	B-Algorithm
camera	I-Algorithm
or	O
camera	O
body	O
is	O
a	O
camera	O
with	O
interchangeable	O
components	O
that	O
constitutes	O
the	O
core	O
of	O
a	O
system	O
.	O
</s>
<s>
Early	O
representatives	O
include	O
Leica	O
I	O
Schraubgewinde	O
(	O
1930	O
)	O
,	O
Exakta	O
(	O
1936	O
)	O
and	O
the	O
Nikon	B-Algorithm
F	I-Algorithm
(	O
1959	O
)	O
.	O
</s>
<s>
System	B-Algorithm
cameras	I-Algorithm
are	O
often	O
single-lens	B-Algorithm
reflex	I-Algorithm
(	O
SLR	B-Algorithm
)	O
or	O
twin-lens	B-Algorithm
reflex	I-Algorithm
(	O
TLR	O
)	O
but	O
can	O
also	O
be	O
rangefinder	B-Algorithm
cameras	I-Algorithm
or	O
,	O
more	O
recently	O
,	O
mirrorless	B-Device
interchangeable-lens	I-Device
cameras	I-Device
.	O
</s>
<s>
Even	O
point-and-shoot	B-Algorithm
cameras	I-Algorithm
usually	O
include	O
a	O
tripod	O
socket	O
.	O
</s>
<s>
A	O
system	B-Algorithm
camera	I-Algorithm
includes	O
at	O
the	O
very	O
least	O
a	O
camera	O
body	O
and	O
separate	O
,	O
interchangeable	O
lenses	O
,	O
whence	O
the	O
alternative	O
name	O
interchangeable-lens	B-Algorithm
camera	I-Algorithm
(	O
ILC	O
)	O
.	O
</s>
<s>
For	O
film	O
cameras	O
,	O
a	O
motor	B-Algorithm
drive	I-Algorithm
to	O
advance	O
the	O
film	O
automatically	O
.	O
</s>
<s>
Interchangeable	O
viewfinders	O
,	O
including	O
interchangeable	O
focusing	O
screens	O
in	O
the	O
case	O
of	O
SLRs	B-Algorithm
.	O
</s>
<s>
While	O
some	O
early	O
mechanical	O
interfaces	O
are	O
standardized	O
across	O
brands	O
,	O
optical	O
and	O
electronic	O
interfaces	O
are	O
often	O
proprietary	B-Device
.	O
</s>
<s>
Hot	B-Algorithm
shoes	I-Algorithm
have	O
a	O
common	O
interface	O
for	O
basic	O
flash	O
functions	O
,	O
but	O
often	O
contain	O
proprietary	B-Device
contacts	O
inside	O
for	O
advanced	O
flashes	O
and	O
data	O
modules	O
.	O
</s>
