<s>
The	O
Mamiya	B-Algorithm
645	I-Algorithm
camera	O
systems	O
are	O
a	O
series	O
of	O
medium	O
format	O
film	O
and	O
digital	B-Device
cameras	I-Device
and	O
lenses	O
manufactured	O
by	O
Mamiya	O
and	O
its	O
successors	O
.	O
</s>
<s>
All	O
seven	O
of	O
the	O
manual-focus	O
Mamiya	B-Algorithm
645	I-Algorithm
cameras	O
can	O
use	O
the	O
same	O
lenses	O
and	O
film	O
inserts	O
(	O
film	O
spools	O
)	O
.	O
</s>
<s>
The	O
M645	O
was	O
a	O
true	O
system	B-Algorithm
camera	I-Algorithm
,	O
with	O
interchangeable	O
viewfinders	O
and	O
lenses	O
.	O
</s>
<s>
The	O
metered	O
prisms	O
read	O
the	O
aperture	B-General_Concept
dial	O
through	O
a	O
mechanical	O
coupling	O
on	O
the	O
lens	O
.	O
</s>
<s>
The	O
Mamiya	B-Algorithm
645	I-Algorithm
Super	O
was	O
manufactured	O
from	O
1985	O
to	O
1993	O
.	O
</s>
<s>
The	O
Mamiya	B-Algorithm
645	I-Algorithm
Pro	O
was	O
manufactured	O
from	O
1993	O
to	O
1998	O
.	O
</s>
<s>
The	O
Mamiya	B-Algorithm
645	I-Algorithm
Pro-TL	I-Algorithm
was	O
manufactured	O
from	O
1997	O
to	O
2006	O
and	O
is	O
functionally	O
similar	O
to	O
the	O
645	O
Pro	O
but	O
adds	O
through-the-lens	O
flash	O
metering	O
.	O
</s>
<s>
The	O
Mamiya	B-Algorithm
645	I-Algorithm
Manual-Focus	O
lenses	O
will	O
work	O
on	O
all	O
manual-focus	O
bodies	O
.	O
</s>
<s>
Third-party	O
adapters	O
exist	O
to	O
use	O
these	O
manual-focus	O
lenses	O
on	O
Nikon	B-Architecture
F	I-Architecture
mount	I-Architecture
,	O
Canon	B-Application
EF	I-Application
mount	I-Application
,	O
and	O
other	O
cameras	O
.	O
</s>
<s>
All	O
Mamiya	B-Algorithm
645	I-Algorithm
lenses	O
are	O
multi-coated	O
.	O
</s>
<s>
Nearly	O
all	O
have	O
curved	O
aperture	B-General_Concept
blades	O
,	O
rendering	O
smooth	O
backgrounds	O
at	O
wider	O
aperture	B-General_Concept
settings	O
.	O
</s>
<s>
All	O
manual-focus	O
lenses	O
for	O
Mamiya	B-Algorithm
645	I-Algorithm
are	O
Sekor	O
C	O
lenses	O
,	O
which	O
Mamiya	O
used	O
to	O
designate	O
multi-coated	O
lenses	O
.	O
</s>
<s>
Many	O
"	O
N	O
"	O
lenses	O
are	O
the	O
same	O
as	O
their	O
prior	O
"	O
C	O
"	O
or	O
"	O
S	O
"	O
lens	O
version	O
,	O
but	O
have	O
changes	O
to	O
the	O
lens	O
coatings	O
and	O
a	O
plastic	O
aperture	B-General_Concept
ring	O
instead	O
of	O
metal	O
.	O
</s>
<s>
timeout	O
)	O
Prism	O
viewfinder	O
AENo0.74xCadmium	O
SulfideEV	O
2.85	O
to	O
EV	O
172	O
sec.1/100025	O
-6400Match	O
NeedleCamera	O
(	O
bullseye	O
mark	O
setting	O
activates	O
Aperture	B-General_Concept
Priority	O
mode	O
)	O
Yes	O
+	O
/	O
-	O
2	O
stopsCameraYes535gSmall	O
ISO	O
knob	O
only	O
,	O
and	O
either	O
a	O
square	O
sliding	O
on-off	O
switch	O
(	O
early	O
)	O
or	O
a	O
white	O
"	O
on	O
"	O
button	O
surrounded	O
by	O
a	O
circular	O
on-off	O
switch	O
(	O
late	O
)	O
.	O
</s>
<s>
**	O
early	O
version	O
has	O
silver	O
"	O
Mamiya	O
"	O
logo	O
on	O
the	O
front	O
,	O
later	O
version	O
has	O
silver	O
"	O
Mamiya	B-Algorithm
645	I-Algorithm
"	O
logo	O
on	O
front	O
.	O
</s>
<s>
The	O
Mamiya	B-Algorithm
645	I-Algorithm
Autofocus	O
(	O
AF	O
)	O
system	O
was	O
launched	O
in	O
1999	O
with	O
the	O
645AF	O
.	O
</s>
<s>
It	O
still	O
used	O
the	O
same	O
lens	O
mount	O
,	O
but	O
the	O
new	O
autofocus	O
lenses	O
did	O
not	O
have	O
an	O
aperture	B-General_Concept
ring	O
;	O
rather	O
,	O
the	O
lens	O
aperture	B-General_Concept
was	O
controlled	O
by	O
dials	O
on	O
the	O
camera	O
.	O
</s>
<s>
If	O
manual	O
focus	O
lenses	O
are	O
used	O
,	O
the	O
lens	O
aperture	B-General_Concept
must	O
be	O
set	O
before	O
metering	O
the	O
scene	O
(	O
known	O
as	O
"	O
stop-down	O
metering	O
"	O
)	O
which	O
made	O
the	O
manual-focus	O
lenses	O
of	O
limited	O
usefulness	O
compared	O
to	O
the	O
newer	O
autofocus	O
lenses	O
.	O
</s>
<s>
Mamiya	O
645AFD	O
(	O
2001	O
)	O
—	O
Added	O
communication	O
interface	O
for	O
digital	B-Device
backs	O
,	O
otherwise	O
similar	O
to	O
the	O
645AF	O
.	O
</s>
<s>
Mamiya	O
645DF	O
(	O
Phase	O
One	O
645DF	O
)	O
(	O
2009	O
)	O
—	O
A	O
completely	O
new	O
camera	O
,	O
but	O
it	O
uses	O
the	O
same	O
lenses	O
as	O
the	O
rest	O
of	O
the	O
Mamiya	B-Algorithm
645	I-Algorithm
AF	O
system	O
.	O
</s>
<s>
Supports	O
more	O
than	O
50	O
different	O
digital	B-Device
backs	O
and	O
80	O
different	O
lenses	O
,	O
including	O
native	O
Mamiya	O
lenses	O
and	O
Hasselblad	B-Algorithm
V	O
lenses	O
.	O
</s>
<s>
Some	O
Mamiya	B-Algorithm
645	I-Algorithm
AF	O
lenses	O
are	O
also	O
sold	O
as	O
Phase	O
One	O
lenses	O
.	O
</s>
