<s>
The	O
Mamiya	B-Algorithm
RB67	I-Algorithm
is	O
a	O
professional	O
medium	O
format	O
single-lens	B-Algorithm
reflex	I-Algorithm
system	O
camera	O
manufactured	O
by	O
Mamiya	O
.	O
</s>
<s>
The	O
RB67	O
Professional	O
was	O
introduced	O
in	O
1970	O
with	O
a	O
similar	O
look	O
to	O
conventional	O
medium	O
format	O
SLR	B-Algorithm
cameras	I-Algorithm
like	O
the	O
Hasselblad	O
,	O
but	O
was	O
larger	O
due	O
to	O
the	O
6×7	O
cm	O
frame	O
format	O
,	O
closer	O
to	O
the	O
typical	O
8×10	O
inch	O
aspect	O
ratio	O
of	O
portraits	O
.	O
</s>
<s>
Focusing	O
is	O
performed	O
with	O
a	O
bellows	B-Algorithm
on	O
the	O
body	O
.	O
</s>
<s>
The	O
RB	O
in	O
the	O
name	O
stands	O
for	O
"	O
Rotating	O
Back	O
"	O
,	O
a	O
concept	O
dating	O
back	O
to	O
early	O
Graflex	B-Algorithm
cameras	O
as	O
early	O
as	O
1907	O
.	O
</s>
<s>
In	O
1957	O
they	O
introduced	O
the	O
Mamiyaflex	O
C	O
which	O
incorporated	O
several	O
common	O
features	O
from	O
large	O
format	O
press	O
cameras	O
:	O
a	O
bellows	B-Algorithm
focussing	O
system	O
,	O
and	O
interchangeable	O
lenses	O
.	O
</s>
<s>
Despite	O
their	O
initial	O
popularity	O
with	O
the	O
press	O
,	O
by	O
the	O
late	O
1960s	O
other	O
companies	O
were	O
successfully	O
producing	O
and	O
marketing	O
medium	O
format	O
SLRs	B-Algorithm
with	O
exchangeable	O
film	O
backs	O
,	O
allowing	O
a	O
photographer	O
to	O
switch	O
film	O
types	O
easily	O
—	O
not	O
needing	O
multiple	O
cameras	O
.	O
</s>
<s>
While	O
several	O
competitors	O
offered	O
medium	O
format	O
SLR	B-Algorithm
cameras	I-Algorithm
,	O
there	O
was	O
not	O
a	O
successful	O
offering	O
with	O
bellows	B-Algorithm
focussing	O
and	O
a	O
rotating	O
back	O
.	O
</s>
<s>
New	O
medium	O
format	O
SLR	B-Algorithm
offerings	O
in	O
the	O
late	O
1960s	O
like	O
the	O
Pentax	O
6×7	O
,	O
began	O
to	O
resemble	O
a	O
conventional	O
35mm	O
SLR	B-Algorithm
cameras	I-Algorithm
,	O
with	O
interchangeable	O
viewfinder	O
and	O
lenses	O
,	O
and	O
horizontal	O
film	O
paths	O
.	O
</s>
<s>
To	O
compete	O
,	O
Mamiya	O
added	O
the	O
RB67	O
alongside	O
their	O
advanced	O
TLR	O
,	O
the	O
C330	O
,	O
but	O
using	O
SLR	B-Algorithm
,	O
a	O
horizontal	O
film	O
path	O
,	O
and	O
exchangeable	O
film	O
magazines	O
,	O
while	O
retaining	O
the	O
bellows	B-Algorithm
focus	O
and	O
front-leaf	O
shutter	O
system	O
.	O
</s>
<s>
The	O
concept	O
is	O
similar	O
in	O
layout	O
to	O
Hasselblad	O
cameras	O
,	O
though	O
the	O
RB67	O
is	O
much	O
larger	O
and	O
heavier	O
,	O
due	O
to	O
the	O
inclusion	O
of	O
traditional	O
professional	O
features	O
such	O
as	O
bellows	B-Algorithm
focussing	O
and	O
the	O
rotating	O
back	O
.	O
</s>
