<s>
The	O
Canon	B-Algorithm
FT	I-Algorithm
QL	I-Algorithm
is	O
a	O
35mm	O
single-lens	B-Algorithm
reflex	I-Algorithm
camera	I-Algorithm
introduced	O
by	O
Canon	O
Inc	O
.	O
in	O
March	O
1966	O
.	O
</s>
<s>
It	O
has	O
a	O
Canon	B-Algorithm
FL	I-Algorithm
lens	I-Algorithm
mount	I-Algorithm
compatible	O
with	O
the	O
large	O
range	O
of	O
FL	O
series	O
lenses	O
.	O
</s>
<s>
FT	O
QL	O
was	O
introduced	O
in	O
March	O
1966	O
,	O
a	O
year	O
after	O
the	O
pellicle	O
mirrored	O
Canon	B-Algorithm
Pellix	I-Algorithm
.	O
</s>
<s>
However	O
it	O
differs	O
from	O
the	O
Pellix	B-Algorithm
models	O
,	O
having	O
a	O
normal	O
quick-return	O
reflex	O
mirror	O
and	O
offering	O
stop-down	O
TTL	O
metering	O
.	O
</s>
<s>
The	O
later	O
Canon	B-Algorithm
F-1	I-Algorithm
has	O
a	O
similar	O
prism	O
for	O
metering	O
in	O
its	O
removable	O
screen	O
.	O
</s>
<s>
The	O
Canon	B-Algorithm
FT	I-Algorithm
viewfinder	O
screen	O
is	O
not	O
user	O
changeable	O
.	O
</s>
<s>
The	O
pentaprism	O
finder	O
is	O
fixed	O
like	O
the	O
similar	O
FX	O
and	O
FP	B-Algorithm
models	O
but	O
unlike	O
some	O
earlier	O
Canon	O
R	O
reflexes	O
.	O
</s>
<s>
An	O
accessory	O
device	O
,	O
the	O
Canon	O
Booster	O
,	O
worked	O
only	O
with	O
the	O
FT	O
QL	O
and	O
Pellix	B-Algorithm
QL	O
.	O
</s>
<s>
It	O
is	O
a	O
plug-in	O
device	O
that	O
sits	O
on	O
the	O
accessory	B-Algorithm
shoe	I-Algorithm
and	O
increases	O
the	O
metering	O
sensitivity	O
by	O
a	O
factor	O
of	O
16	O
for	O
measuring	O
exposure	O
in	O
poor	O
light	O
.	O
</s>
<s>
The	O
Canon	B-Algorithm
FT	I-Algorithm
is	O
one	O
of	O
a	O
series	O
of	O
three	O
basically	O
identical	O
cameras	O
released	O
around	O
this	O
time	O
.	O
</s>
<s>
The	O
first	O
was	O
the	O
Canon	B-Algorithm
FX	I-Algorithm
which	O
had	O
a	O
built-in	O
meter	O
,	O
but	O
no	O
through-the-lens	O
(	O
TTL	O
)	O
metering	O
,	O
instead	O
using	O
a	O
window	O
on	O
the	O
camera	O
body	O
front	O
.	O
</s>
<s>
The	O
later	O
entry	O
level	O
FP	B-Algorithm
has	O
no	O
built-in	O
meter	O
.	O
</s>
<s>
The	O
final	O
model	O
was	O
the	O
top	O
of	O
this	O
sector	O
,	O
the	O
Canon	B-Algorithm
FT	I-Algorithm
QL	I-Algorithm
,	O
which	O
was	O
developed	O
to	O
combat	O
the	O
growing	O
popularity	O
of	O
the	O
Pentax	B-Algorithm
Spotmatic	I-Algorithm
variants	O
as	O
well	O
as	O
the	O
Topcon	O
RE	O
SLRs	B-Algorithm
.	O
</s>
<s>
During	O
the	O
production	O
run	O
of	O
the	O
Canon	B-Algorithm
FT	I-Algorithm
QL	I-Algorithm
,	O
Canon	O
quietly	O
upgraded	O
some	O
components	O
and	O
made	O
minor	O
cosmetic	O
changes	O
.	O
</s>
