<s>
The	O
Nikon	O
F-501	O
(	O
sold	O
in	O
North	O
America	O
as	O
the	O
N2020	O
)	O
was	O
the	O
first	O
successful	O
autofocus	O
SLR	B-Algorithm
camera	I-Algorithm
sold	O
by	O
the	O
Nikon	O
Corporation	O
beginning	O
in	O
1986	O
.	O
</s>
<s>
A	O
nearly	O
identical	O
,	O
albeit	O
manual	O
focus	O
version	O
,	O
called	O
the	O
Nikon	B-Algorithm
F-301	I-Algorithm
(	O
N2000	B-Algorithm
in	O
North	O
America	O
)	O
was	O
also	O
available	O
.	O
</s>
<s>
Subsequent	O
models	O
in	O
the	O
consumer	O
line	O
included	O
the	O
Nikon	B-Algorithm
F-401	I-Algorithm
,	O
Nikon	B-Algorithm
F-601	I-Algorithm
,	O
and	O
Nikon	B-Algorithm
F-801	I-Algorithm
/	O
F-801s	B-Algorithm
.	O
</s>
<s>
The	O
F-501	O
is	O
a	O
35	O
mm	O
single-lens	B-Algorithm
reflex	I-Algorithm
camera	I-Algorithm
with	O
automatic	O
film	O
loading	O
and	O
advance	O
,	O
almost	O
a	O
first	O
for	O
Nikon	O
(	O
the	O
F-301	B-Algorithm
was	O
their	O
first	O
SLR	B-Algorithm
to	O
feature	O
this	O
)	O
.	O
</s>
<s>
The	O
built-in	O
motor	B-Algorithm
drive	I-Algorithm
provides	O
single	O
(	O
one	O
exposure	O
and	O
frame	O
advance	O
per	O
shutter	O
button	O
press	O
)	O
or	O
continuous	O
(	O
shutter	O
will	O
fire	O
and	O
film	O
will	O
advance	O
so	O
long	O
as	O
the	O
shutter	O
button	O
is	O
depressed	O
)	O
modes	O
.	O
</s>
<s>
The	O
F-501	O
is	O
powered	O
by	O
four	O
AAA	B-Algorithm
batteries	I-Algorithm
housed	O
in	O
the	O
bottom	O
of	O
the	O
camera	O
body	O
,	O
although	O
it	O
can	O
utilize	O
AA	B-Algorithm
sized	O
batteries	O
with	O
an	O
optional	O
attachment	O
(	O
MB-3	O
)	O
.	O
</s>
<s>
Unlike	O
active	O
systems	O
,	O
which	O
set	O
approximate	O
focus	O
based	O
on	O
distance	O
to	O
the	O
subject	O
,	O
the	O
"	O
passive	O
"	O
system	O
uses	O
a	O
CCD	B-Algorithm
to	O
"	O
see	O
"	O
the	O
focus	O
subject	O
and	O
focus	O
in	O
a	O
manner	O
similar	O
to	O
a	O
human	O
operator	O
.	O
</s>
<s>
The	O
F-501	O
can	O
be	O
set	O
for	O
auto	O
exposure	O
,	O
"	O
hi-speed	O
"	O
auto	O
exposure	O
,	O
"	O
dual	O
"	O
auto-exposure	O
(	O
with	O
AI-S	O
type	O
lenses	O
)	O
which	O
switches	O
between	O
regular	O
auto	O
exposure	O
and	O
hi-speed	O
autoexposure	O
based	O
on	O
the	O
lens	O
attached	O
,	O
aperture	B-Algorithm
priority	I-Algorithm
,	O
or	O
full	O
manual	O
exposure	O
modes	O
,	O
which	O
allow	O
the	O
user	O
to	O
set	O
both	O
the	O
aperture	B-General_Concept
and	O
shutter	O
speeds	O
.	O
</s>
<s>
The	O
shutter	O
speed	O
and	O
auto-exposure	O
modes	O
are	O
set	O
by	O
the	O
use	O
of	O
a	O
dial	O
on	O
the	O
top	O
of	O
the	O
camera	O
,	O
while	O
the	O
aperture	B-General_Concept
ring	O
on	O
the	O
lens	O
is	O
used	O
for	O
aperture	B-General_Concept
control	O
.	O
</s>
<s>
The	O
"	O
hi-speed	O
"	O
auto-exposure	O
tends	O
to	O
favor	O
higher	O
shutter	O
speeds	O
and	O
wider	O
aperture	B-General_Concept
settings	O
than	O
the	O
"	O
normal	O
"	O
auto	O
exposure	O
mode	O
,	O
while	O
the	O
"	O
dual	O
"	O
mode	O
offers	O
"	O
normal	O
"	O
auto-exposure	O
with	O
lenses	O
at	O
focal	O
lengths	O
less	O
than	O
135mm	O
and	O
"	O
hi-speed	O
"	O
auto-exposure	O
if	O
a	O
lens	O
is	O
longer	O
than	O
135mm	O
.	O
</s>
<s>
Like	O
all	O
Nikon	O
SLRs	B-Algorithm
,	O
the	O
F-501	O
accepts	O
Nikon	O
's	O
F-mount	B-Architecture
lenses	O
,	O
but	O
will	O
only	O
autofocus	O
with	O
lenses	O
designated	O
"	O
AF.	O
"	O
</s>
<s>
Also	O
new	O
to	O
this	O
model	O
is	O
the	O
addition	O
of	O
an	O
extended	O
grip	O
on	O
the	O
shutter	O
button	O
side	O
of	O
the	O
camera	O
body	O
,	O
a	O
feature	O
which	O
has	O
grown	O
in	O
subsequent	O
autofocus	O
SLR	B-Algorithm
camera	I-Algorithm
designs	O
ever	O
since	O
.	O
</s>
<s>
Nikon	O
adopted	O
some	O
design	O
concepts	O
from	O
the	O
F501	O
in	O
the	O
company	O
's	O
first	O
professional	O
autofocus	O
SLR	B-Algorithm
,	O
the	O
Nikon	B-Algorithm
F4	I-Algorithm
,	O
in	O
1988	O
.	O
</s>
<s>
The	O
stripe	O
first	O
appeared	O
in	O
the	O
Nikon	B-Algorithm
F3	I-Algorithm
in	O
1980	O
,	O
and	O
some	O
variation	O
of	O
it	O
has	O
been	O
a	O
design	O
feature	O
of	O
every	O
Nikon	O
autofocus	O
camera	O
since	O
,	O
but	O
on	O
the	O
F-501	O
the	O
stripe	O
is	O
horizontal	O
rather	O
than	O
vertical	O
for	O
the	O
first	O
time	O
.	O
</s>
