<s>
The	O
Sigma	O
18-35mm	O
f/1.8	O
DC	O
HSM	O
Art	O
lens	O
is	O
a	O
fast	O
,	O
constant-aperture	O
wide	O
standard	O
zoom	O
lens	O
made	O
by	O
Sigma	O
Corporation	O
.	O
</s>
<s>
This	O
lens	O
,	O
at	O
its	O
time	O
of	O
manufacturing	O
,	O
was	O
considered	O
a	O
game	O
changer	O
due	O
to	O
it	O
being	O
the	O
only	O
standard	O
zoom	O
boasting	O
a	O
constant	O
f/1.8	O
aperture	B-General_Concept
.	O
</s>
<s>
The	O
lens	O
was	O
designed	O
specifically	O
for	O
crop	O
body	O
DSLRs	B-Device
enabling	O
a	O
crop	O
factor	O
adjusted	O
(	O
full	O
frame	O
equivalent	O
)	O
of	O
f/2.88	O
for	O
Canon	O
or	O
f/2.7	O
for	O
Nikon	B-Algorithm
crop	O
body	O
DSLRs	B-Device
across	O
an	O
equivalent	O
range	O
of	O
28mm-56mm	O
(	O
Canon	O
full	O
frame	O
adjusted	O
)	O
or	O
27mm-53mm	O
(	O
Nikon	B-Algorithm
full	O
frame	O
adjusted	O
)	O
.	O
</s>
