<s>
It	O
uses	O
an	O
EF	B-Application
mount	I-Application
,	O
and	O
is	O
compatible	O
with	O
the	O
Canon	B-Algorithm
EOS	I-Algorithm
camera	O
range	O
.	O
</s>
<s>
It	O
has	O
a	O
focal	B-Algorithm
length	I-Algorithm
of	O
1200mm	O
and	O
so	O
on	O
a	O
digital	B-Application
body	O
with	O
a	O
sensor	O
size	O
of	O
22.5mm	O
×	O
15mm	O
(	O
called	O
1.6	O
×	O
crop	O
)	O
,	O
such	O
as	O
a	O
Canon	B-Device
EOS	I-Device
40D	I-Device
or	O
450D	B-Algorithm
,	O
it	O
provides	O
a	O
35mm	O
field	O
of	O
view	O
equivalent	O
to	O
that	O
of	O
a	O
1920mm	O
lens	O
.	O
</s>
<s>
With	O
a	O
body	O
with	O
a	O
sensor	O
size	O
of	O
28.8mm	O
×	O
19.2mm	O
(	O
called	O
1.3	O
×	O
crop	O
)	O
,	O
such	O
as	O
a	O
Canon	B-Algorithm
EOS-1D	I-Algorithm
Mark	I-Algorithm
IV	I-Algorithm
,	O
the	O
field	O
of	O
view	O
is	O
equivalent	O
to	O
that	O
of	O
a	O
1560mm	O
lens	O
.	O
</s>
<s>
Canon	O
described	O
it	O
as	O
"	O
the	O
world	O
’s	O
largest	O
interchangeable	O
SLR	O
AF	O
lens	O
,	O
in	O
terms	O
of	O
both	O
focal	B-Algorithm
length	I-Algorithm
and	O
maximum	O
aperture.	O
"	O
</s>
<s>
The	O
lens	O
was	O
first	O
developed	O
for	O
the	O
Canon	B-Algorithm
FD	I-Algorithm
mount	I-Algorithm
,	O
although	O
never	O
marketed	O
until	O
after	O
Canon	O
had	O
transitioned	O
to	O
the	O
EF	B-Application
mount	I-Application
.	O
</s>
<s>
Later	O
in	O
the	O
1980s	O
,	O
these	O
lenses	O
were	O
converted	O
to	O
the	O
EF	B-Application
mount	I-Application
.	O
</s>
<s>
The	O
official	O
website	O
of	O
Canon	O
competitor	O
Nikon	B-Algorithm
implies	O
that	O
these	O
lenses	O
,	O
with	O
the	O
built-in	O
1.4x	O
teleconverter	O
,	O
were	O
also	O
used	O
by	O
photographers	O
covering	O
baseball	O
games	O
,	O
including	O
the	O
very	O
popular	O
high	O
school	O
tournaments	O
,	O
at	O
Japan	O
's	O
Koshien	O
Stadium	O
.	O
</s>
<s>
Nikon	B-Algorithm
developed	O
a	O
1200	O
–	O
1700mm	O
manual-focus	O
super	O
telephoto	O
zoom	O
,	O
specifically	O
designed	O
for	O
use	O
at	O
that	O
stadium	O
,	O
in	O
order	O
to	O
compete	O
with	O
Canon	O
's	O
offering	O
.	O
</s>
<s>
The	O
maximum	O
aperture	B-General_Concept
of	O
5.6	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>
It	O
is	O
compatible	O
with	O
the	O
Canon	B-Algorithm
Extender	I-Algorithm
EF	I-Algorithm
teleconverters	O
.	O
</s>
<s>
A	O
list	O
of	O
owners	O
has	O
also	O
never	O
been	O
made	O
public	O
,	O
but	O
reported	O
owners	O
include	O
Sports	O
Illustrated	O
magazine	O
(	O
two	O
)	O
;	O
Canon	O
Professional	O
Services	O
(	O
two	O
)	O
;	O
James	O
Jannard	O
,	O
the	O
billionaire	O
founder	O
of	O
Oakley	O
and	O
RED	O
Digital	B-Application
Cinema	O
(	O
two	O
)	O
;	O
and	O
the	O
National	O
Geographic	O
Society	O
(	O
at	O
least	O
one	O
for	O
its	O
magazine	O
)	O
.	O
</s>
