<s>
The	O
M1	O
,	O
which	O
followed	O
the	O
original	O
M3	B-Algorithm
and	O
later	O
M2	B-Algorithm
,	O
was	O
the	O
lowest-cost	O
and	O
simplest	O
Leica	B-Algorithm
M	I-Algorithm
body	O
,	O
a	O
simplified	O
M2	B-Algorithm
without	O
a	O
rangefinder	O
.	O
</s>
<s>
It	O
was	O
intended	O
to	O
be	O
used	O
for	O
technical	O
work	O
together	O
with	O
the	O
ground-glass	O
focussing	O
Visoflex	O
,	O
a	O
mirror	O
reflex	O
housing	O
that	O
turns	O
a	O
Leica	B-Algorithm
M	I-Algorithm
into	O
a	O
single-lens	O
reflex	O
camera	O
.	O
</s>
