<s>
The	O
Faint	B-Algorithm
Object	I-Algorithm
Camera	I-Algorithm
(	O
FOC	O
)	O
was	O
a	O
camera	O
installed	O
on	O
the	O
Hubble	O
Space	O
Telescope	O
from	O
launch	O
in	O
1990	O
until	O
2002	O
.	O
</s>
<s>
It	O
was	O
replaced	O
by	O
the	O
Advanced	B-Algorithm
Camera	I-Algorithm
for	I-Algorithm
Surveys	I-Algorithm
.	O
</s>
<s>
Rather	O
than	O
CCDs	O
the	O
FOC	O
used	O
photon-counting	O
digicons	O
as	O
its	O
detector	O
.	O
</s>
<s>
thumbnail|Pluto	O
and	O
its	O
moon	O
Charon	O
revealed	O
by	O
the	O
Hubble	O
Faint	B-Algorithm
Object	I-Algorithm
Camera	I-Algorithm
(	O
1994	O
)	O
thumb|The	O
"	O
Einstein	O
cross	O
"	O
,	O
discovered	O
in	O
1985	O
by	O
J	O
.	O
Huchra	O
,	O
is	O
a	O
large	O
gravitational	O
lens	O
.	O
</s>
