Frequently Asked Questions
WHAT IS MILLISECOND
SERVICE GOOD FOR
The service is for
creating ultra slow motion shots for visual effects. The camera system
can shoot over a broad speed range; anywhere between 120 to 12,000 frames
per second, selectable in 12 fps increments. It allows you to slow action
down up to 500 times to get slow motion visual effects never before possible.
This camera is a great alternative to existing high speed cameras because
is easier to control, takes very
sharp pictures, can use timed flash
illumination instead of hot flood lighting, and doesn't waste any
film.
HOW IS THE
MILLISECOND CAMERA DIFFERENT
Instead of moving film
from a supply reel to a take-up reel, this camera continuously spins a
90 inch loop of film around inside the camera housing. This means film
transport can be done at over 500 miles per hour.
This is not
a prism camera. The image is relayed to the film plane through a rotating
mirror, not a prism. This prevents unwanted refraction of the image and
better agreement between the film plane and the image plane during exposure,
resulting in sharper pictures.
WHAT KIND OF
MAGAZINE DOES IT USE
It doesn't use a magazine.
Instead, you use the film loader to
load a 90 inch strip of film off a roll and then load it into a light
tight cassette. You then use this
cassette to load the strip of
film into the camera and recover it after exposure. So instead of one
or two takes off a 1000 foot roll, like with existing high speed cameras,
you can get about 50 takes off a 400 foot roll.
WHAT KIND OF
LENSES DOES IT USE
The camera has a Nikon
mount, an Arri PL mount and a Panavision PV mount. It will accept any
lens of these types. With the Arri and Panavision mounts, the mounts for
matte box rods are in the standard location.
DOES
IT HAVE A VIDEO TAP
Yes.
The viewer system includes a C-mount port for video tap, and a standard
color video camera with 30fps output. The image can be sent to the video
tap through the viewer mirror for set up and composition. During the shot,
the image can be simultaneously fed to the video tap through a 10% pellicle
mirror. This pellicle mirror is removable if you do not need to monitor
the shot on video and want all available light to go to the film.
For many
shots, 30 fps video is not fast enough to be really useful. High speed
video cameras with C-mounts (which are nearly all of them) can be used
to monitor the shot at faster speeds.
HOW DO I SET
EXPOSURE
Exposure is set like
any other cinema camera. The camera's minimum F-number is f 2.8. There
is a one stop loss through the optical system, so the minimum T-number
is t4. It's maximum shutter angle is 80º adjustable down to 10º.
Image quality is slightly sharper at shutter angles below 60º.
CAN I SHOOT
OUTSIDE
Yes. You can shoot
outside, though you need a lot of light. Most high speed shots are lit
to levels well above sunlight. Also, when you shoot very fast, exposure
times become very short. The amount of light needed to make an exposure
at these speeds is more than sunlight for standard film stocks. Adding
lights or pushing the stock may become necessary. Also, the faster you
shoot, the more frames are exposed during the time it takes the shutter
to open at the start of the shot, and to close at the end. With continuous
light, either sunlight or studio light, this results in frames. The faster
you shoot, the more frames will be partially exposed (twenty frames at
the top speed).
CAN'T I JUST
DO THIS ON A COMPUTER
You can draw about
anything on a computer. But in order to recreate chaotic or turbulent
events like smoke coming from a gunshot, it takes a lot of time and skill
(i.e. expense) to get them to look real and not cartoonish. The Millisecond
camera captures images of the actual event, yielding an impact and realism
which is very difficult to reproduce. This is especially true for the
faster subjects where action happens in a time domain that is generally
unfamiliar. The difficulty of re-creating the way things flex and vibrate
and flow in this time domain should not be underestimated. Digital post
production can be very useful to interpolate, enhance, combine and compose
the images for greater effect, but it is no replacement for a direct film
record of reality.
WHAT ARE THE
LIMITATIONS
There are no limitations
on the type of film used, the composition of shots, or subject matter.
Apart from the following constraints, the method is very similar to conventional
cinematography. You are limited to 120 frames, or five seconds of screen
time. This is because film transport is done by spinning a 90 inch loop
of film (120 frames' worth) around continuously instead of pulling film
from a supply reel to a take-up reel. As you might expect, you cannot
do a rack focus or a pan during the shot. This is because shots typically
last only several milliseconds (thousandths of a second) and moving lenses
or tripods at this speed is not possible, especially because the camera
is also a massive flywheel. (Anyone remember the gyroscopic effect from
high school physics?)
IF THE FILM
GOES AROUND IN A CIRCLE, HOW DO I KNOW WHERE THE HEAD IS
The camera generates
a timing pulse when the head of the film is in front of the optics. This
pulse is used to initiate the shot for subjects that can be accurately
triggered, like a pyro, or for continuous subjects which are being sampled,
like a stream of water. For shots where you cannot control the exact timing,
like the impact of falling objects or bullets out of guns, the camera
is slaved to the event and will start shooting automatically. However,
there is no controlling where the beginning of the loop of film may be
at this instant. With these types of subjects, you get an occasional splitting
of the shot from top to bottom . The shot may sometimes start in the middle
of the film, run off the end and finish up at the top, requiring a splice
to reconfigure the shot. Where possible, it is best to do several takes
of these types of subjects in order to maximize the likelihood that you
will get a reasonable sequence of action on a continuous piece of film.
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