تويت
التصوير الفوتوغرافي الحديث
صنع صور متحركة للتلفزيون
إضافة الصوت
مسجل شريط منفصل
الشريط المغناطيسي
ADDING THE SOUND
There are a number of ways in which sound may be added to a motion picture - a separate tape recorder may be used , a layer of magnetic oxide such as is used on sound tape may be applied in a thin stripe film , or an optical sound track may be printed photographically alongside the picture . We will discuss all three methods in the following pages .
SEPARATE TAPE RECORDER
This is the simplest of all methods and requires no further explanation than the one given earlier in this Assignment and also in Assignment 19. The major problem when using a separate tape recorder is to get the recorder and the projector into reasonably good synchronization ( sync ) . The first step is to operate . both projector and recorder from the same wall outlet and use one switch to turn on both simultaneously . Allow them to warm up first and then start both the film and tape together . The tape should start through the machine a little before there is any sound on it , so that the tape can come up to speed before any sound is heard . This simple method will not give perfect synchronization , of course , but it may be good enough for background music or for short films where extreme accuracy is not at all necessary .
For better synchronization , there are a number of special attachments on the market which may be used to advantage . Some of these operate mechanically while others are electronic in nature . They will give you fairly close synchronization and , therefore , work quite nicely for offstage narration or for background music . None of them , however , are really good enough for lip synchronization , which must be absolutely perfect . An error in synchronization of even one or two frames is noticeable and this requires a degree of precision which is impossible to maintain with ordinary tapes .
MAGNETIC STRIPE
RECORDER With this method , a thin stripe of magnetic oxide , the active material in ordinary recording tape , is applied close to one edge of the film for its entire length . Since the stripe becomes an integral part of the film , it cannot get out of synchronization .
The general practice is to edit the film completely so that it is ready for projection . It is then sent to the laboratory which adds the magnetic stripe .
There are a number of magnetic sound projectors on the market which permit the recording of sound such as narration or background music while the magnetically striped film is being run through .
You can obtain unexposed film with a magnetic stripe so that sound can be recorded on it in the camera while the film is being exposed . Sound recorded in this manner is called single system sound . This , of course , results in perfect lip sync , but it has two extremely strong disadvantages ; there are very few cameras on the market which are made to use this type of film , and very little cutting or editing of the film is possible , since cutting the film also cuts the sound track . Also , the sound for any particular frame of film is not recorded alongside that frame , but a few inches ahead of it . This is made necessary by the way the film travels through the camera or projector .
If you will recall the explanation of how film is exposed in a movie camera which appeared at the beginning of Assignment 19 , you will remember that the film is drawn through the film gate in a series of rapid jerks and not in one continuous motion . This is fine insofar as making a good picture is concerned , but it is completely wrong for recording sound which requires an absolutely uniform motion of the recording medium . This means that the sound must be recorded and played back at some point beyond the sprocket wheels which feed the film through the film gate . The sprockets take up the slack in the film provided for the intermittent claw action .
Standards have been established for the separation between a frame of picture and the corresponding point on the sound track . The sound is always ahead of the picture to which it corresponds ( except in professional cinemascope movies ) by a specific number of frames . The separation for the various films and sound systems is shown in Table I.
One final point about magnetic sound . If you do your own recording , you need not adhere to the standard speed of 24 frames per second for sound movies . If , for example , you already have a film which was shot at either 16 or 18 frames per second , you can still add sound to it merely by running it through the projector at that speed while you record the sound . Of course , the sound will not be as good at this low speed so that if you expect to add sound to your films , it is much better to shoot at 24 frames per second to begin with .
صنع صور متحركة للتلفزيون
إضافة الصوت
مسجل شريط منفصل
الشريط المغناطيسي
ADDING THE SOUND
There are a number of ways in which sound may be added to a motion picture - a separate tape recorder may be used , a layer of magnetic oxide such as is used on sound tape may be applied in a thin stripe film , or an optical sound track may be printed photographically alongside the picture . We will discuss all three methods in the following pages .
SEPARATE TAPE RECORDER
This is the simplest of all methods and requires no further explanation than the one given earlier in this Assignment and also in Assignment 19. The major problem when using a separate tape recorder is to get the recorder and the projector into reasonably good synchronization ( sync ) . The first step is to operate . both projector and recorder from the same wall outlet and use one switch to turn on both simultaneously . Allow them to warm up first and then start both the film and tape together . The tape should start through the machine a little before there is any sound on it , so that the tape can come up to speed before any sound is heard . This simple method will not give perfect synchronization , of course , but it may be good enough for background music or for short films where extreme accuracy is not at all necessary .
For better synchronization , there are a number of special attachments on the market which may be used to advantage . Some of these operate mechanically while others are electronic in nature . They will give you fairly close synchronization and , therefore , work quite nicely for offstage narration or for background music . None of them , however , are really good enough for lip synchronization , which must be absolutely perfect . An error in synchronization of even one or two frames is noticeable and this requires a degree of precision which is impossible to maintain with ordinary tapes .
MAGNETIC STRIPE
RECORDER With this method , a thin stripe of magnetic oxide , the active material in ordinary recording tape , is applied close to one edge of the film for its entire length . Since the stripe becomes an integral part of the film , it cannot get out of synchronization .
The general practice is to edit the film completely so that it is ready for projection . It is then sent to the laboratory which adds the magnetic stripe .
There are a number of magnetic sound projectors on the market which permit the recording of sound such as narration or background music while the magnetically striped film is being run through .
You can obtain unexposed film with a magnetic stripe so that sound can be recorded on it in the camera while the film is being exposed . Sound recorded in this manner is called single system sound . This , of course , results in perfect lip sync , but it has two extremely strong disadvantages ; there are very few cameras on the market which are made to use this type of film , and very little cutting or editing of the film is possible , since cutting the film also cuts the sound track . Also , the sound for any particular frame of film is not recorded alongside that frame , but a few inches ahead of it . This is made necessary by the way the film travels through the camera or projector .
If you will recall the explanation of how film is exposed in a movie camera which appeared at the beginning of Assignment 19 , you will remember that the film is drawn through the film gate in a series of rapid jerks and not in one continuous motion . This is fine insofar as making a good picture is concerned , but it is completely wrong for recording sound which requires an absolutely uniform motion of the recording medium . This means that the sound must be recorded and played back at some point beyond the sprocket wheels which feed the film through the film gate . The sprockets take up the slack in the film provided for the intermittent claw action .
Standards have been established for the separation between a frame of picture and the corresponding point on the sound track . The sound is always ahead of the picture to which it corresponds ( except in professional cinemascope movies ) by a specific number of frames . The separation for the various films and sound systems is shown in Table I.
One final point about magnetic sound . If you do your own recording , you need not adhere to the standard speed of 24 frames per second for sound movies . If , for example , you already have a film which was shot at either 16 or 18 frames per second , you can still add sound to it merely by running it through the projector at that speed while you record the sound . Of course , the sound will not be as good at this low speed so that if you expect to add sound to your films , it is much better to shoot at 24 frames per second to begin with .
تعليق