Operating Instructions
to
dissolve-Fade
out,
wind
back
the
film;
then
fade
in
.
Standard
dissolves
contain
either
40
frames
(about
2V2
seconds
at
speed 16)
or
60
frames
(about
3%
seconds
at
speed 16).
For
most
purposes
you
can
gage
the
duration
of
the
fade
·
out
and
fade
·
in
by
counting.
When
exposing
at
16
frames
per
second, two complete
turns
of
the
eight·frame
shaft
are
required
to
wind
back
the
film
exposed
in
one
second.
When
exposing
at
24
frames
per
second,
three
complete
turns
wind
back
the
film
exposed
in
one
second.
other uses of
the
variable
shutter
®
CLOSED
t§
'I.·OPEN
~
'h
· OPEN
0-
OPEN
A
wide
number
of effects
can
be
obtained
by
using
the
variable
shutter.
The
principle
of
the
shutter
is
as
follows:
When
the
film is
being
exposed
at
16
frames
per
second
with
the
shutter
at
OPEN,
the
exposure
to
each
individual
frame
is 1/35
second;
at
V2-0PEN,
the
ex-
posure
is
about
1/70 second,
or
:1f2
the
exposure
of
OPEN.
The
other
controls affecting
exposure
(camera
speed
and
lens
opening)
also
change
in
multiples of
two-f/8
admits
twice
as
much
light
as
//11,
and
speed
32
is twice as fast as
speed
16.
For
this
reason
it is simple
to
keep
the
exposure
at
the
correct
value
while
changing
one
or
more
of
the
exposure-govern-
ing
factors.
For
example, a
certain
exposure
calls
for
16
frames
per
second
with
a lens
opening
of
//11.
If
y
ou
wish
to
change
the
shutter
speed
to
32
frames
per
second
(twice
the
speed of 16),
it
is necessary
to
adjust
the
lens
opening
to
//8
(twice
the
light
admitted
at
//11) .
Similarly,
if
you
wish
to
change
the
shutter
open-
ing
to
:1f2-0PEN,
you
can
maintain
the
same
relative
exposure
at
16
frames
per
second
by
changing
the
lens
opening
to
//8.
EXPOSURE
TIME
PER
FRAME
Angle
0/
EXPOSURE
TIME
IN
SECONDS
Adjust- Opening
8
16
24
32
ment
0/
~n
Single Frames
Frames
Frames Frames
Shutter
Shutter··
Degrees
Frames per per per per
Second
Second
Second
Second
OPEN
165
1/17 1/17 1/35
1/52
1/70
lh
OPEN
82.5
1/35 1/35
1/70 1/105 1/140
14
OPEN
41.25
1/70 1/70
1/140
1/210 1/280
64
Frames
per
Second
1/140
1/280
1/560