<s>
A	O
pellicle	B-Algorithm
mirror	I-Algorithm
is	O
an	O
ultra-thin	O
,	O
ultra-lightweight	O
semi-transparent	O
mirror	O
employed	O
in	O
the	O
light	O
path	O
of	O
an	O
optical	O
instrument	O
,	O
splitting	O
the	O
light	O
beam	O
into	O
two	O
separate	O
beams	O
,	O
both	O
of	O
reduced	O
light	O
intensity	O
.	O
</s>
<s>
In	O
photography	O
,	O
the	O
pellicle	B-Algorithm
mirror	I-Algorithm
has	O
been	O
employed	O
in	O
single-lens	B-Algorithm
reflex	I-Algorithm
(	O
SLR	B-Algorithm
)	O
cameras	O
,	O
at	O
first	O
to	O
enable	O
through-the-lens	O
exposure	O
measurement	O
and	O
possibly	O
to	O
reduce	O
camera	O
shake	O
,	O
but	O
later	O
most	O
successfully	O
to	O
enable	O
fast	O
series	O
photography	O
,	O
which	O
otherwise	O
would	O
be	O
slowed	O
down	O
by	O
the	O
movement	O
of	O
the	O
reflex	O
mirror	O
,	O
while	O
maintaining	O
constant	O
finder	O
vision	O
.	O
</s>
<s>
The	O
first	O
use	O
of	O
pellicle	B-Algorithm
mirrors	I-Algorithm
for	O
consumer	O
photography	O
however	O
were	O
in	O
color	O
separation	O
cameras	O
.	O
</s>
<s>
The	O
Devin	O
Tricolor	O
Camera	O
from	O
at	O
least	O
the	O
1938	O
version	O
used	O
two	O
pellicle	B-Algorithm
mirrors	I-Algorithm
plus	O
three	O
color	O
filters	O
to	O
split	O
the	O
image	O
from	O
a	O
single	B-Algorithm
lens	I-Algorithm
into	O
three	O
images	O
of	O
the	O
three	O
additive	O
primary	O
colors	O
.	O
</s>
<s>
Pellicle	B-Algorithm
mirrors	I-Algorithm
are	O
ideal	O
for	O
this	O
purpose	O
,	O
even	O
today	O
,	O
since	O
they	O
are	O
lighter	O
and	O
cheaper	O
than	O
an	O
optical	O
block	O
of	O
dichroic	O
prisms	O
,	O
which	O
would	O
be	O
heavy	O
and	O
expensive	O
for	O
large	O
,	O
high	O
resolution	O
film	O
or	O
plates	O
.	O
</s>
<s>
The	O
conventional	O
SLR	B-Algorithm
camera	I-Algorithm
has	O
a	O
reflex	O
mirror	O
directing	O
the	O
light	O
beam	O
from	O
the	O
lens	O
to	O
the	O
focusing	O
screen	O
in	O
the	O
viewfinder	O
,	O
which	O
is	O
swung	O
out	O
of	O
the	O
light	O
path	O
when	O
the	O
exposure	O
is	O
made	O
and	O
causing	O
the	O
viewfinder	O
to	O
go	O
dark	O
.	O
</s>
<s>
The	O
first	O
camera	O
to	O
employ	O
the	O
pellicle	B-Algorithm
mirror	I-Algorithm
as	O
a	O
beam	O
splitter	O
for	O
the	O
viewfinder	O
was	O
the	O
Canon	B-Algorithm
Pellix	I-Algorithm
,	O
launched	O
by	O
Canon	O
Camera	O
Company	O
Inc	O
.	O
Japan	O
in	O
1965	O
.	O
</s>
<s>
That	O
employed	O
a	O
CdS	B-Device
meter	O
cell	O
placed	O
behind	O
the	O
reflex	O
mirror	O
that	O
had	O
narrow	O
slits	O
cut	O
into	O
the	O
surface	O
to	O
let	O
the	O
light	O
reach	O
the	O
cell	O
.	O
</s>
<s>
The	O
Pellix	B-Algorithm
pellicle	B-Algorithm
mirror	I-Algorithm
was	O
an	O
ultra-thin	O
(	O
0.02mm	O
)	O
Mylar	O
film	O
with	O
a	O
vapour	O
deposited	O
semi	O
reflecting	O
layer	O
.	O
</s>
<s>
The	O
next	O
35mm	O
SLR	B-Algorithm
camera	I-Algorithm
to	O
employ	O
the	O
pellicle	B-Algorithm
mirror	I-Algorithm
was	O
the	O
Canon	B-Algorithm
F-1	I-Algorithm
High	I-Algorithm
Speed	I-Algorithm
,	O
made	O
available	O
in	O
the	O
event	O
of	O
the	O
1972	O
Olympic	O
games	O
,	O
the	O
object	O
being	O
rapid	O
series	O
photography	O
,	O
difficult	O
at	O
the	O
time	O
to	O
obtain	O
with	O
a	O
moving	O
mirror	O
.	O
</s>
<s>
The	O
mirror	O
design	O
was	O
the	O
same	O
as	O
in	O
the	O
Pellix	B-Algorithm
.	O
</s>
<s>
In	O
1984	O
,	O
Canon	O
released	O
another	O
version	O
of	O
their	O
then	O
"	O
New	O
F-1	O
"	O
,	O
which	O
attained	O
a	O
record	O
14	O
frames	O
per	O
second	O
performance	O
,	O
being	O
the	O
fastest	O
analog	O
SLR	B-Algorithm
of	O
that	O
time	O
.	O
</s>
<s>
Nippon	B-Algorithm
Kogaku	I-Algorithm
KK	I-Algorithm
,	I-Algorithm
Japan	I-Algorithm
introduced	O
their	O
high-speed	O
Nikon	B-Algorithm
F2H	I-Algorithm
in	O
1976	O
.	O
</s>
<s>
Two	O
further	O
Canon	O
models	O
were	O
produced	O
with	O
pellicle	B-Algorithm
mirrors	I-Algorithm
,	O
the	O
EOS	B-Algorithm
RT	I-Algorithm
and	O
the	O
EOS-1N	B-Algorithm
RS	O
,	O
the	O
RT	O
being	O
based	O
on	O
the	O
EOS	O
600/EOS	O
630	O
and	O
the	O
1N	O
RS	O
being	O
based	O
on	O
the	O
EOS-1N	B-Algorithm
.	O
</s>
<s>
As	O
development	O
of	O
SLR	B-Algorithm
cameras	I-Algorithm
has	O
progressed	O
since	O
these	O
early	O
models	O
,	O
fast	O
sequence	O
shooting	O
has	O
apparently	O
become	O
possible	O
using	O
ordinary	O
moving	O
mirrors	O
in	O
high-speed	O
cameras	O
,	O
getting	O
rid	O
of	O
the	O
vulnerable	O
pellicle	B-Algorithm
mirror	I-Algorithm
that	O
was	O
prone	O
to	O
dust	O
and	O
dirt	O
.	O
</s>
<s>
The	O
mirror	O
mechanism	O
of	O
conventional	O
SLR	B-Algorithm
cameras	I-Algorithm
has	O
improved	O
since	O
the	O
Pellix	B-Algorithm
mirror	O
was	O
introduced	O
;	O
the	O
viewfinder	O
is	O
dark	O
for	O
only	O
a	O
very	O
short	O
time	O
,	O
the	O
shutter	O
lag	O
is	O
small	O
,	O
and	O
the	O
mirror-return	O
is	O
fast	O
enough	O
for	O
rapid	O
shooting	O
.	O
</s>
<s>
Digital	O
SLR	B-Algorithm
cameras	I-Algorithm
are	O
able	O
to	O
take	O
ten	O
frames	O
or	O
more	O
per	O
second	O
employing	O
an	O
instant-return	O
mirror	O
.	O
</s>
<s>
Sony	O
has	O
introduced	O
cameras	O
with	O
plastic	O
pellicle-like	O
mirrors	O
,	O
which	O
it	O
describes	O
as	O
"	O
Single-Lens	B-Algorithm
Translucent	O
"	O
cameras	O
.	O
</s>
<s>
These	O
cameras	O
divert	O
a	O
portion	O
of	O
incoming	O
light	O
to	O
a	O
phase-detection	O
autofocus	O
unit	O
,	O
while	O
the	O
remaining	O
light	O
strikes	O
a	O
digital	B-Algorithm
image	I-Algorithm
sensor	I-Algorithm
.	O
</s>
<s>
Sony	O
"	O
SLT	O
"	O
cameras	O
employ	O
an	O
electronic	B-Algorithm
viewfinder	I-Algorithm
(	O
EVF	O
)	O
allowing	O
exposure	O
value	O
,	O
white	B-Algorithm
balance	I-Algorithm
and	O
other	O
settings	O
to	O
be	O
verified	O
and	O
adjusted	O
visually	O
before	O
taking	O
a	O
picture	O
,	O
although	O
typically	O
the	O
EVF	O
displays	O
far	O
less	O
dynamic	O
range	O
than	O
the	O
sensor	O
.	O
</s>
<s>
"	O
SLT	O
"	O
cameras	O
also	O
lack	O
a	O
real-time	O
view	O
at	O
high	O
shooting	O
rates	O
,	O
when	O
the	O
viewfinder	O
shows	O
the	O
last	O
picture	O
taken	O
instead	O
of	O
the	O
one	O
being	O
taken	O
—	O
a	O
phenomenon	O
comparable	O
to	O
certain	O
older	O
SLRs	B-Algorithm
that	O
can	O
only	O
achieve	O
their	O
maximum	O
burst	O
rate	O
in	O
mirror	O
lock-up	O
.	O
</s>
<s>
Few	O
film	O
movie	O
cameras	O
have	O
been	O
made	O
that	O
make	O
use	O
of	O
the	O
pellicle	B-Algorithm
mirror	I-Algorithm
.	O
</s>
<s>
In	O
the	O
Soviet	O
Union	O
in	O
1970	O
appeared	O
the	O
Kiev	O
16	O
Alpha	O
,	O
also	O
featuring	O
a	O
pellicle	B-Algorithm
mirror	I-Algorithm
finder	O
system	O
that	O
deflects	O
strictly	O
vertically	O
.	O
</s>
<s>
Advantages	O
of	O
a	O
pellicle	B-Algorithm
mirror	I-Algorithm
:	O
</s>
<s>
Disadvantages	O
of	O
a	O
pellicle	B-Algorithm
mirror	I-Algorithm
:	O
</s>
<s>
Owing	O
to	O
its	O
thinness	O
,	O
the	O
pellicle	B-Algorithm
mirror	I-Algorithm
is	O
fragile	O
,	O
making	O
it	O
difficult	O
to	O
clean	O
.	O
</s>
