<s>
In	O
photography	O
,	O
the	O
single-lens	B-Algorithm
reflex	I-Algorithm
camera	I-Algorithm
(	O
SLR	B-Algorithm
)	O
is	O
provided	O
with	O
a	O
mirror	O
to	O
redirect	O
light	O
from	O
the	O
picture	O
taking	O
lens	O
to	O
the	O
viewfinder	O
prior	O
to	O
releasing	O
the	O
shutter	O
for	O
composing	O
and	O
focusing	O
an	O
image	O
.	O
</s>
<s>
No	O
SLR	B-Algorithm
camera	I-Algorithm
before	O
1954	O
had	O
this	O
feature	O
,	O
although	O
the	O
mirror	O
on	O
some	O
early	O
SLR	B-Algorithm
cameras	I-Algorithm
was	O
entirely	O
operated	O
by	O
the	O
force	O
exerted	O
on	O
the	O
shutter	O
release	O
and	O
only	O
returned	O
when	O
the	O
finger	O
pressure	O
was	O
released	O
.	O
</s>
<s>
The	O
Asahiflex	B-Algorithm
II	I-Algorithm
,	O
released	O
by	O
Japanese	O
company	O
Asahi	B-Application
(	O
Pentax	B-Application
)	O
in	O
1954	O
,	O
was	O
the	O
world	O
's	O
first	O
SLR	B-Algorithm
camera	I-Algorithm
with	O
an	O
instant	B-Algorithm
return	I-Algorithm
mirror	I-Algorithm
.	O
</s>
