Note: Descriptions are shown in the official language in which they were submitted.
WOg4/23339 2 15 9 S 8 ~ PCT~K94/00136
Method of simultaneous recording of pictures and sound and a
camera for carrying out the method.
The invention relates to a method for the recordiny
of pictures, preferably living pictures, by means of a camera
and simultanous recording of sound connected to the pictures
by means of one or more microrhonec being displaceable in
relation to the camera.
The invention also relates to an embodiment of a
camera and one or more microphones for carrying out the
method.
By carrying out the prior known method of recor-
ding of pictures and sound the location of the microphones
depend on and is limited by the recording field of the
camera, and the size of this recording field ~ren~ on the
lens system of the camera, of its adjustment for focusing in
the recording field, and of the size and shape of the
normally rectangular field of vision of the camera. Sound for
films and TV is normally recorded by a sound assistant
guiding a microphone being suspended at the end of a movable
long rod, above the heads of the actors. It is the task of
the sound assistant to guide the microphone so that it
~ follows the actor as closely as possible in the recording
field of the camera, but without the microphone being visible
in said field. By cameras carried on a camera dolly, and by
which zoom objectives are used, the boundary surfaces of the
recording field are so varying that it takes a great ex-
perience and expertise to guide a microphone optimally. Since
a sound volume fades with the c~Con~ power of the distance
from a sound source, a displacement of only 20 cm of the
location of a microphone in relation to the sound source may
be crucial for the quality of a sound recording.
By carrying out the known method it frequently
happens that a microphone unfortunately is taken into the
recording field of a camera, which means that a new recording
must be made.
It is the purpose of the invention to reduce the
W094/23339 ~ ~ ~ 9S PCT~K94/00136
risk of a microphone being taken into the recording field of
a camera during the recording of pictures and sound.
The method according to the invention is charac-
terized in that one or more signal wave fields are formed,
each passing closely outside or touching a boundary surface
for the recording field of the camera, that signals for the
formation of said signal wave fields are emitted from one or
more signal wave transmitters, and that the signals might be
received and transmitted on e.g. by reflection from one or
more microphones to respective microphone-guiding receivers
by the reflected signals.
Thereby it is achieved that some signal fields can
be arranged around an area to be filmed. According to the
invention the signals may consist of sound waves or of
electromagnetic waves, e.g. light or radio waves. The
reflected signals can be conceived by the eyes or ears of a
microphone operator or received by an apparatus converting
the signals so that the operator can conceive them, or which
apparatus automatically guides a microphone. If a microphone
then is about to be taken into the area to be filmed, the
microphone will already have entered a signal field and
therefrom have transmitted, e.g. reflected a signal, which
informs a signal receiver, e.g. a microphone operator, that
now the limit of the microphone displacement has been
reached. It is thereby possible to prevent a microphone being
entered into the recording field and to prevent a new
recording having to be made due to a microphone having been
erroneously guided. The signal wave fields may also be placed
inthe very area to be filmed and may possibly confine the
actual area. The signals for this may be ultrasonic signals
or signals based upon infrared light.
An embodiment of a camera and one or more micropho-
nes for carrying out the method may, according to the
invention, be characterized in that one or more signal
transmitters is or are mounted in respective holders on the
camera, and that one or more microphones has or have means
for receiving and sending on of the signals received from the
W094/~339 ~ PCT~Kg4/00136
- ... 21~9~82
signal transmitters.
Since the signal transmitters thereby have been
arranged so clossly to the camera as possible is achieved
that the signal fields can be arranged closely to the
normally rectangular recording field of the camera. The
warning signals from the reflecting means will not be
apparent until the microphones are quite close to the
recording field. The displaceability of the microphones will
thereby be limited as little as possible. Since the signal
transmitters have been mounted on the camera, the location of
the signal fields in relation to the recording field will
1~ -in unchanged during the displacements or motions of the
camera.
An embs~i ent of a camera and one or more micropho-
nes may according to the invention also be characterized in
that one or more of the signal wave transmitters is or are
laser light transmitters transmitting laser light of a
wavelength of about 800 nm and being adapted so that the
signals are emitted forward in relation to the camera in one
or more fan or carpet shaped b~lnches of laser beams, and
equipped with guiding means to guide the direction of a light
bunch concurrently with an alteration of the adjustment of
the camera optics so that the light bunch intersects the
picture field plane corresponding to the camera optics in a
belt situated outside, preferably immediately outside and
parallel to one side, preferably an upper side of the picture
field corresponding to the optics, and that the microphones
have been provided with laser light reflecting zones,
preferably in the form of fluorescent plates.
Thereby an optimum effect is achieved, namely that
well defined signal fields may be arranged quite closely to
the recording field of the camera, that the laser light is
nearly invisible to the human eye and totally invisible for
the emulsion of a film and the picture tube of a TV camera,
and that a fluorescent zone or plate is sh; ni ng powerfully,
e.g. in the form of a luminous line, when it is hit by laser
light and thereby gets clearly visible for a microphone
W094~339 PCT~K94/00136
2~;S9S~2
operat~r, immediately before the microphone has reached a
boundary surface for the recording field of the camera.
The invention will now be described in more detail
in connection with an embodiment of a camera or one or more
microphones for carrying out the method according to the
invention and with reference to the drawing, in which
fig. 1 shows a camera with a zoom-objective, a laser light
transmitter and a microphone with a flourescent plate,
fig. 2 shows the laser light transmitter seen from outside,
and
fig. 3 shows the inner parts of the laser light transmitter.
Fig. 1 shows a camera 2 with a signal wave field
source, here in the form of a laser light transmitter 1, the
latter being arranged in a holder 8 on the camera 2. The
laser light transmitter 1 emits or transmits a fan or carpet
shaped bunch of laser light having a wavelength of about 800
nm. The carpet intersects the plane of the picture field 5 of
the camera 2 in a belt 3 lying parallelly with and immediate-
ly outside the upper side of the picture field. A microphone
6 which can be guided manually by a microphone operator, has
been provided with a flourescent zone or fluorescent plate 7
mounted at the lower edge of the microphone. The microphone
6 has been shown in a position in which its fluorescent plate
is situated immediately above the fan or carpet shaped bunch
of laser light waves. If the microphone 6 is lowered from
this position and down into the light bunch, the fluorescent
plate 7 will at once be hit by laser light. The fluorescent
effect of the plate will make it shine powerfully when hit by
the almost invisible laser light. The reflecting light will
be visible at a distance of at least 20 m from the camera,
even in broad sl~nsh~ne. Thus, the microphone operator gets a
visible warning if the microphone is about to be taken from
above into the picture field of the camera.
If the location of the aforementioned belt 3 should
be maintained in the picture field plane of the camera in a
position immediately above the picture field after an
alteration of the optics, the inclination 12 between the
W094/~339 2 PCT~Kg4/00136
s9~
lower side of the carpet formed light bunch and the centre
line of the camera optics should be altered as a function of
amendments in the optics.
Adjustment of the inclination 12 of the laser light
transmitter may e.g. be made by means of bushbuttons 9
located at the upper side of the laser light transmitter 1,
and which relate to the sizes of the optics used, cf. fig. 2.
The mechanical adjustment is made by means of a
step motor 10 with a threaded shaft 11 which amend the in-
clination 12 of the laser light transmitter. By a push on oneof the pushbuttons 9 for a given size of the optics, a
microprocessor 13 transmits a corresponding number of
impulses to the step motor lO, which makes a given number of
rotations for achieving the correct inclination 12, cf. fig.
3, and thus a location of the belt 3 immediately above the
upper side of the relevant picture field. When a zoom
objective is used, an impulse transmitter 14 is mounted in
engagement with the toothed rim 15 which a priori has been
used for motor adjustment of the picture size, cf. fig. 1.
When a zoom elector button 16 on the upper side of the laser
light transmitter, cf. fig. 2, has been pushed, the signals
from the impulse transmitter 14 will be transmitted to the
step motor lO in such a way that the inclination 12 is
amended synchronously with the amendments of the zoom
objective so that the belt is located as mentioned above.
In order to compensate for mechanical variations by
different cameras and zoom objectives and for permitting a
zone of a few centimeters, in which the fluorescent plate 7
of the microphone is illuminated without being part of the
picture, the laser light transmitter l has a 0-point adjust-
ment 17 with the opportunity of a manual adjustment up and
down of the inclination 12.
The laser light transmitter may have dimensions as
a large matchbox. It might via a change-over switch 18 be
supplied with current, either from internal batteries or from
the current supply of the camera.
If sound waves are used for the signal wave
W094/23339 PCT~K94/~136
; ~2il59 ~ 82 6
transmitters, said sound waves are preferably within the
ultra short wave area, permitting the formation of a well
defined fan or carpet shaped signal field. Here the micropho-
nes themselves may transmit ultra sound signals together with
the sound recorded. After the ultra sound signals having been
filtrated from the microphone signals, they can be processed
and caused to form audible or visible signals for the
microphone operator or guiding signals for a microphone
guiding robot.
The reason for the selection of laser light with a
wavelength of about 800 nm, e.g. + 10~ is that said light -
contrary to visible laser light, is invisible to the human
eye and to the picture tube of a TV camera as well, and can
practically not influence an unexposed film emulsion. This
particular laser light can be made visible by hitting a
surface being treated with a fluorescent material which only
shines powerfully, when light of this particular wavelength
hits it. C~c~quently~ when a microphone is hit by the carpet
formed bunch of laser light beams, a warning stripe of light
will be formed on the microphone itself.
The invention is not limited to the use of laser
light as source of the signal wave field, since other sources
as mentioned above may be used. The signal wave field does
not need to be placed outside the recording field, but may be
inside as well as outside, surrounding this field.l
