<s>
The	O
Asahiflex	B-Algorithm
was	O
a	O
35	O
mm	O
single-lens	B-Algorithm
reflex	I-Algorithm
camera	I-Algorithm
built	O
by	O
the	O
Asahi	O
Optical	O
Corporation	O
(	O
later	O
to	O
become	O
Pentax	B-Application
)	O
.	O
</s>
<s>
It	O
was	O
regarded	O
as	O
the	O
first	O
SLR	B-Algorithm
camera	I-Algorithm
built	O
in	O
Japan	O
.	O
</s>
<s>
Instead	O
,	O
Asahi	O
decided	O
to	O
copy	O
the	O
Praktiflex	B-Algorithm
,	O
a	O
1939	O
design	O
,	O
made	O
in	O
the	O
German	O
Democratic	O
Republic	O
.	O
</s>
<s>
Asahi	O
's	O
designers	O
(	O
Nobuyuki	O
Yoshida	O
and	O
Ryohei	O
Suzuki	O
)	O
were	O
convinced	O
of	O
the	O
inherent	O
superiority	O
of	O
the	O
SLR	B-Algorithm
and	O
so	O
proceeded	O
along	O
these	O
lines	O
.	O
</s>
<s>
This	O
effort	O
resulted	O
in	O
the	O
Asahiflex	B-Algorithm
I	I-Algorithm
,	O
which	O
was	O
also	O
the	O
first	O
Japanese	O
35	O
mm	O
SLR	B-Algorithm
.	O
</s>
<s>
The	O
Asahiflex	B-Algorithm
I	I-Algorithm
had	O
a	O
non-interchangeable	O
waist-level	O
viewfinder	O
,	O
with	O
a	O
direct	O
optical	O
viewfinder	O
for	O
eye-level	O
use	O
.	O
</s>
<s>
Like	O
the	O
Praktiflex	B-Algorithm
the	O
Asahiflex	B-Algorithm
I	I-Algorithm
do	O
not	O
have	O
a	O
returning	O
mirror	O
(	O
which	O
means	O
the	O
mirror	O
will	O
only	O
be	O
back	O
to	O
its	O
initial	O
position	O
to	O
redirect	O
light	O
to	O
the	O
viewfinder	O
for	O
composing	O
and	O
range	O
finding	O
work	O
after	O
the	O
operators	O
had	O
wound	O
the	O
film	O
)	O
and	O
shutter	O
speeds	O
from	O
1/20	O
to	O
1/500	O
and	O
B	O
.	O
</s>
<s>
The	O
Asahiflex	B-Algorithm
I	I-Algorithm
went	O
through	O
some	O
minor	O
modifications	O
for	O
flash	O
use	O
,	O
resulting	O
in	O
the	O
IA	O
.	O
</s>
<s>
The	O
Asahiflex	B-Algorithm
IIB	I-Algorithm
was	O
released	O
in	O
1954	O
.	O
</s>
<s>
It	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>
<s>
The	O
problem	O
of	O
mirror	O
black-out	O
was	O
one	O
of	O
the	O
main	O
problems	O
with	O
prior	O
SLR	B-Algorithm
designs	O
,	O
greatly	O
reducing	O
usability	O
and	O
leading	O
to	O
the	O
greater	O
popularity	O
of	O
the	O
rangefinder	O
.	O
</s>
<s>
With	O
the	O
final	O
model	O
in	O
the	O
series	O
,	O
the	O
IIA	O
,	O
the	O
Asahiflex	B-Algorithm
gained	O
slow	O
speeds	O
from	O
1/25th	O
of	O
a	O
second	O
to	O
1/2	O
of	O
a	O
second	O
.	O
</s>
