<s>
Video	O
cameras	O
can	O
possess	O
a	O
function	O
called	O
black	B-Algorithm
balance	I-Algorithm
which	O
calibrates	O
the	O
signal	O
for	O
no	O
light	O
,	O
just	O
as	O
they	O
have	O
a	O
"	O
white	B-Algorithm
balance	I-Algorithm
"	O
function	O
which	O
gives	O
reference	O
to	O
true	O
white	O
to	O
the	O
CCDs	O
.	O
</s>
<s>
Unlike	O
white	B-Algorithm
balance	I-Algorithm
,	O
black	B-Algorithm
balance	I-Algorithm
is	O
not	O
adjusted	O
every	O
time	O
.	O
</s>
<s>
The	O
main	O
purpose	O
of	O
black	B-Algorithm
balance	I-Algorithm
is	O
to	O
eliminate	O
any	O
residual	O
current	O
being	O
output	O
from	O
the	O
pixel	O
sites	O
under	O
conditions	O
of	O
complete	O
darkness	O
,	O
often	O
referred	O
to	O
as	O
thermal	O
noise	O
.	O
</s>
<s>
This	O
is	O
why	O
the	O
camera	O
automatically	O
closes	O
the	O
iris	O
completely	O
when	O
it	O
does	O
the	O
black	B-Algorithm
balance	I-Algorithm
.	O
</s>
<s>
Conditions	O
under	O
which	O
black	B-Algorithm
balance	I-Algorithm
are	O
typically	O
done	O
are	O
when	O
the	O
camera	O
experiences	O
a	O
large	O
change	O
in	O
operating	O
temperature	O
,	O
especially	O
from	O
colder	O
to	O
warmer	O
.	O
</s>
<s>
With	O
CMOS	B-Architecture
sensor	I-Architecture
technology	O
,	O
black	O
balancing	O
may	O
not	O
be	O
as	O
necessary	O
as	O
it	O
is	O
with	O
CCD	B-Algorithm
type	O
devices	O
.	O
</s>
<s>
It	O
is	O
common	O
to	O
talk	O
about	O
how	O
clean	O
and	O
relatively	O
noise	O
free	O
CMOS	B-Architecture
sensors	I-Architecture
are	O
by	O
design	O
.	O
</s>
<s>
Amateur	O
handycam	O
users	O
need	O
not	O
worry	O
about	O
black	B-Algorithm
balance	I-Algorithm
.	O
</s>
<s>
have	O
a	O
switch	O
which	O
has	O
to	O
be	O
flicked	O
upwards	O
to	O
do	O
the	O
white	B-Algorithm
balance	I-Algorithm
.	O
</s>
<s>
The	O
same	O
switch	O
when	O
pressed	O
downwards	O
does	O
a	O
black	B-Algorithm
balance	I-Algorithm
.	O
</s>
<s>
In	O
the	O
Panasonic	O
102	O
3ccd	O
series	O
,	O
the	O
white	B-Algorithm
balance	I-Algorithm
switch	O
when	O
pressed	O
just	O
once	O
triggers	O
white	B-Algorithm
balancing	I-Algorithm
and	O
when	O
depressed	O
and	O
held	O
for	O
a	O
few	O
seconds	O
completes	O
the	O
black	B-Algorithm
balance	I-Algorithm
.	O
</s>
<s>
Most	O
camera	O
operators	O
never	O
touch	O
the	O
black	B-Algorithm
balance	I-Algorithm
.	O
</s>
<s>
Black	B-Algorithm
balance	I-Algorithm
can	O
be	O
done	O
if	O
the	O
colours	O
do	O
not	O
seem	O
to	O
be	O
truly	O
represented	O
even	O
after	O
doing	O
the	O
white	B-Algorithm
balance	I-Algorithm
.	O
</s>
<s>
There	O
is	O
a	O
lot	O
of	O
debate	O
on	O
whether	O
it	O
is	O
necessary	O
to	O
do	O
the	O
black	B-Algorithm
balance	I-Algorithm
every	O
time	O
.	O
</s>
<s>
Panasonic	O
102	O
XB	O
camera	O
operating	O
instructions	O
manual	O
suggests	O
that	O
black	B-Algorithm
balance	I-Algorithm
be	O
performed	O
when	O
:	O
</s>
