<s>
The	O
B4	B-Algorithm
lens	I-Algorithm
mount	I-Algorithm
was	O
standardized	O
in	O
1992	O
by	O
the	O
Broadcasting	O
Technology	O
Association	O
(	O
BTA	O
)	O
and	O
is	O
defined	O
in	O
BTA	O
S-1005	O
.	O
</s>
<s>
The	O
B4	B-Algorithm
mount	I-Algorithm
defines	O
the	O
sensor	O
to	O
have	O
a	O
diagonal	O
size	O
of	O
11	O
mm	O
(	O
a	O
so-called	O
2/3	O
"	O
size	O
sensor	O
)	O
.	O
</s>
<s>
The	O
B4-mount	B-Algorithm
is	O
used	O
by	O
practically	O
all	O
2/3	O
"	O
broadcast	O
lenses	O
and	O
cameras	O
(	O
as	O
of	O
2019	O
)	O
.	O
</s>
<s>
Although	O
the	O
standard	O
was	O
set	O
in	O
1992	O
,	O
the	O
B4	B-Algorithm
mount	I-Algorithm
already	O
existed	O
before	O
1980	O
.	O
</s>
<s>
The	O
Sony	O
BVP-300	O
,	O
produced	O
from	O
1978	O
,	O
was	O
possibly	O
the	O
first	O
camera	O
with	O
a	O
B4	B-Algorithm
mount	I-Algorithm
.	O
</s>
<s>
Further	O
,	O
all	O
Sony	O
Betacam	O
cameras	O
had	O
a	O
B4	B-Algorithm
mount	I-Algorithm
.	O
</s>
<s>
The	O
BTA	O
was	O
formed	O
by	O
Japanese	O
broadcaster	O
NHK	O
and	O
included	O
members	O
from	O
Canon	O
,	O
Fuji	O
,	O
Hitachi	O
,	O
Ikegami	O
,	O
JVC	O
,	O
Matsushita	O
(	O
Panasonic	O
)	O
,	O
Nikon	B-Algorithm
,	O
Sony	O
and	O
Toshiba	O
.	O
</s>
<s>
The	O
B4-mount	B-Algorithm
has	O
its	O
image	O
projected	O
at	O
48	O
mm	O
behind	O
the	O
lens	O
mount	O
flange	O
(	O
in	O
air	O
)	O
.	O
</s>
