<s>
The	O
Nikon	B-Algorithm
SP	I-Algorithm
is	O
a	O
professional	O
level	O
,	O
interchangeable	O
lens	O
,	O
35	O
mm	O
film	O
,	O
rangefinder	B-Algorithm
camera	I-Algorithm
introduced	O
in	O
1957	O
.	O
</s>
<s>
It	O
is	O
the	O
culmination	O
of	O
Nikon	B-Algorithm
's	O
rangefinder	B-Algorithm
development	O
which	O
started	O
in	O
1948	O
with	O
the	O
Nikon	B-Algorithm
I	I-Algorithm
,	O
and	O
was	O
"	O
arguably	O
the	O
most	O
advanced	O
rangefinder	B-Algorithm
of	O
its	O
time.	O
"	O
</s>
<s>
It	O
was	O
manufactured	O
by	O
the	O
Japanese	O
optics	O
company	O
Nippon	O
Kogaku	O
K	O
.	O
K	O
.	O
(	O
Nikon	B-Algorithm
Corporation	O
since	O
1988	O
)	O
.	O
</s>
<s>
Three	O
other	O
lower	O
featured	O
rangefinder	B-Algorithm
models	O
were	O
subsequently	O
produced	O
on	O
the	O
SP	O
frame	O
,	O
and	O
production	O
continued	O
into	O
the	O
1960s	O
,	O
but	O
further	O
development	O
of	O
Nikon	B-Algorithm
's	O
professional	O
rangefinders	B-Algorithm
ended	O
with	O
the	O
introduction	O
and	O
success	O
of	O
the	O
single	B-Algorithm
lens	I-Algorithm
reflex	I-Algorithm
Nikon	B-Algorithm
F	I-Algorithm
in	O
1959	O
.	O
</s>
<s>
In	O
2005	O
2,500	O
models	O
of	O
a	O
repro	O
model	O
were	O
manufactured	O
under	O
the	O
name	O
of	O
"	O
Nikon	B-Algorithm
SP	I-Algorithm
Limited	O
Edition	O
"	O
.	O
</s>
<s>
The	O
Nikon	B-Algorithm
SP	I-Algorithm
has	O
dual	O
viewfinders	O
providing	O
frame	O
lines	O
for	O
a	O
total	O
of	O
six	O
focal	O
lengths	O
.	O
</s>
<s>
The	O
camera	O
uses	O
Nikon	B-Algorithm
's	O
'	B-Algorithm
S	I-Algorithm
 '	I-Algorithm
bayonet	I-Algorithm
lens	I-Algorithm
mount	I-Algorithm
which	O
is	O
a	O
modified	O
Contax	O
'	O
C	O
 '	O
bayonet	O
and	O
Contax	O
'	O
C	O
 '	O
lenses	O
are	O
physically	O
compatible	O
but	O
do	O
not	O
accurately	O
focus	O
with	O
the	O
built-in	O
rangefinder	B-Algorithm
.	O
</s>
<s>
The	O
camera	O
does	O
not	O
have	O
a	O
flash	O
sync	O
on	O
its	O
hot	B-Algorithm
shoe	I-Algorithm
.	O
</s>
<s>
In	O
1959	O
the	O
shutter	O
curtain	O
was	O
changed	O
to	O
titanium	O
similar	O
to	O
the	O
Nikon	B-Algorithm
F	I-Algorithm
.	O
</s>
<s>
This	O
made	O
the	O
SP	O
the	O
first	O
rangefinder	B-Algorithm
to	O
have	O
motorized	O
film	O
advance	O
.	O
</s>
<s>
The	O
Nikon	B-Algorithm
F	I-Algorithm
SLR	B-Algorithm
of	O
1959	O
has	O
many	O
structural	O
similarities	O
to	O
the	O
SP	O
from	O
which	O
it	O
evolved	O
with	O
the	O
addition	O
of	O
a	O
reflex	O
mirror	O
and	O
interchangeable	O
pentaprism	O
viewfinder	O
.	O
</s>
