<s>
The	O
EF	B-Application
50mm	O
lenses	O
are	O
a	O
group	O
of	O
normal	O
prime	O
lenses	O
made	O
by	O
Canon	O
that	O
share	O
the	O
same	O
focal	B-Algorithm
length	I-Algorithm
.	O
</s>
<s>
The	O
50mm	O
focal	B-Algorithm
length	I-Algorithm
,	O
when	O
used	O
with	O
a	O
35mm	O
film	O
or	O
full-frame	O
sensor	O
,	O
has	O
been	O
widely	O
considered	O
to	O
match	O
the	O
perspective	O
seen	O
by	O
the	O
human	O
eye	O
.	O
</s>
<s>
Canon	O
50mm	O
lenses	O
have	O
an	O
EF	B-Application
type	O
mount	O
that	O
fits	O
the	O
Canon	B-Algorithm
EOS	I-Algorithm
line	O
of	O
cameras	O
.	O
</s>
<s>
When	O
pairing	O
a	O
50mm	O
lens	O
to	O
a	O
Canon	O
DSLR	O
with	O
an	O
APS-C	B-Algorithm
sized	O
sensor	O
,	O
the	O
crop	O
factor	O
effectively	O
turns	O
the	O
50mm	O
focal	B-Algorithm
length	I-Algorithm
into	O
an	O
80mm	O
field	O
of	O
view	O
.	O
</s>
<s>
Seven	O
EF	B-Application
50mm	O
lenses	O
have	O
been	O
sold	O
by	O
Canon	O
:	O
</s>
<s>
It	O
was	O
the	O
fastest	O
SLR	B-Algorithm
lens	O
in	O
production	O
during	O
its	O
lifetime	O
.	O
</s>
<s>
In	O
common	O
with	O
the	O
EF	B-Algorithm
85mm	I-Algorithm
f/1.2L	I-Algorithm
USM	I-Algorithm
it	O
uses	O
an	O
electronic	O
"	O
focus	O
by	O
wire	O
"	O
system	O
and	O
requires	O
power	O
from	O
the	O
camera	O
in	O
order	O
to	O
manual	O
focus	O
.	O
</s>
<s>
The	O
8-blade	O
diaphragm	O
and	O
maximum	O
aperture	B-General_Concept
of	O
1.0	O
give	O
this	O
lens	O
the	O
ability	O
to	O
create	O
extremely	O
shallow	O
depth	O
of	O
field	O
effects	O
and	O
to	O
support	O
low	O
light	O
situations	O
.	O
</s>
<s>
Despite	O
its	O
price	O
and	O
large	O
maximum	O
aperture	B-General_Concept
,	O
the	O
1.0L	O
was	O
not	O
a	O
particularly	O
sharp	O
lens	O
at	O
any	O
aperture	B-General_Concept
,	O
and	O
the	O
two	O
cheaper	O
50mm	O
options	O
offered	O
far	O
better	O
sharpness	O
when	O
stopped	O
down	O
beyond	O
about	O
2.8	O
.	O
</s>
<s>
A	O
circular	O
,	O
8-blade	O
diaphragm	O
and	O
maximum	O
aperture	B-General_Concept
of	O
1.2	O
give	O
this	O
lens	O
the	O
ability	O
to	O
create	O
very	O
shallow	O
depth	O
of	O
field	O
effects	O
with	O
smooth	O
background	O
blur	O
.	O
</s>
<s>
It	O
is	O
the	O
least	O
expensive	O
1.4	O
aperture	B-General_Concept
lens	O
that	O
Canon	O
currently	O
manufactures	O
.	O
</s>
<s>
An	O
8-blade	O
diaphragm	O
and	O
maximum	O
aperture	B-General_Concept
of	O
1.4	O
give	O
this	O
lens	O
the	O
ability	O
to	O
create	O
shallow	O
depth	O
of	O
field	O
effects	O
.	O
</s>
<s>
A	O
5	O
blade	O
maximum	O
aperture	B-General_Concept
of	O
1.8	O
gives	O
this	O
lens	O
the	O
ability	O
to	O
create	O
depth	O
of	O
field	O
effects	O
.	O
</s>
<s>
Note	O
that	O
this	O
housing	O
and	O
use	O
of	O
a	O
5-blade	O
aperture	B-General_Concept
were	O
shared	O
with	O
the	O
EF28mm	O
2.8	O
and	O
EF35mm	O
2	O
lenses	O
,	O
in	O
the	O
case	O
of	O
the	O
latter	O
to	O
speed	O
date	O
of	O
release	O
and	O
keep	O
production	O
costs	O
low	O
.	O
</s>
<s>
This	O
lens	O
utilizes	O
Canon	O
's	O
STM	O
(	O
STepper	B-Algorithm
Motor	I-Algorithm
)	O
focusing	O
mechanism	O
,	O
which	O
supports	O
the	O
Movie	O
Servo	O
autofocus	O
mode	O
.	O
</s>
<s>
The	O
lens	O
features	O
a	O
metal	O
mount	O
and	O
has	O
a	O
rounded	O
seven-blade	O
aperture	B-General_Concept
.	O
</s>
<s>
The	O
optional	O
Life-Size	O
Converter	O
EF	B-Application
adapts	O
the	O
lens	O
to	O
produce	O
a	O
maximum	O
magnification	O
of	O
1:1	O
.	O
</s>
<s>
Attaching	O
the	O
converter	O
increases	O
the	O
lens	O
focal	B-Algorithm
length	I-Algorithm
to	O
70mm	O
,	O
reduces	O
the	O
maximum	O
aperture	B-General_Concept
to	O
3.5	O
and	O
limits	O
the	O
focal	O
range	O
.	O
</s>
<s>
Attribute	O
1.0L	O
USM	O
1.2L	O
USM	O
1.4	O
USM	O
Image150px150px150pxKey	O
features	O
Full-frame	B-Algorithm
compatible	I-Algorithm
15px|Yes	O
Yes	O
Image	O
stabilizer	O
15px|No	O
No	O
Ultrasonic	O
Motor	O
15px|Yes	O
Yes	O
Stepping	B-Algorithm
Motor	I-Algorithm
15px|No	O
No	O
L-series	O
15px|Yes	O
Yes	O
15px|No	O
No	O
Diffractive	O
Optics	O
15px|No	O
No	O
Macro	O
15px|No	O
NoTechnical	O
data	O
Aperture	B-General_Concept
(	O
max-min	O
)	O
1.0-16	O
1.2-16	O
1.4-22	O
Construction	O
9	O
groups	O
/	O
11	O
elements	O
6	O
groups	O
/	O
8	O
elements	O
6	O
groups	O
/	O
7	O
elements	O
#	O
of	O
diaphragm	O
blades	O
8	O
Closest	O
focusing	O
distance	O
2	O
ft	O
/	O
0.6m	O
1.5	O
ft	O
/	O
0.45m	O
Max	O
.	O
</s>
<s>
Attribute	O
1.8	O
1.8	O
II	O
1.8	O
STM	O
2.5	O
Compact	O
Macro	O
Image150px150px150px150pxKey	O
features	O
Full-frame	B-Algorithm
compatible	I-Algorithm
15px|Yes	O
Yes	O
Image	O
stabilizer	O
15px|No	O
No	O
Ultrasonic	O
Motor	O
15px|No	O
No	O
Stepping	B-Algorithm
Motor	I-Algorithm
15px|No	O
No	O
15px|Yes	O
Yes	O
15px|No	O
No	O
L-series	O
15px|No	O
No	O
Diffractive	O
Optics	O
15px|No	O
No	O
Macro	O
15px|No	O
No	O
15px|Yes	O
Yes	O
(	O
1:2	O
)	O
Technical	O
data	O
Aperture	B-General_Concept
(	O
max-min	O
)	O
1.8-22	O
2.5-32	O
Construction	O
5	O
groups	O
/	O
6	O
elements	O
8	O
groups	O
/	O
9	O
elements	O
#	O
of	O
diaphragm	O
blades	O
5	O
7	O
6	O
Closest	O
focusing	O
distance	O
1.5	O
ft	O
/	O
0.45m	O
1.15	O
ft	O
/	O
0.35m	O
0.749	O
ft	O
/	O
0.228m	O
Max	O
.	O
</s>
