Figuring Out How to Create Optical Film Sound: A History of Motion-Picture Sound Recording
The shift from silent films to an entirely new era of motion pictures in which sound-on-film recording, also known as optical sound, would prevail represents a unique point in the history of filmmaking. Early steps toward learning how to create optical film sound that was initially focused on military use. Would ultimately become the most prevalent sound recording method for motion picture films. Optical sound, or sound-on-film format, was widely popular in the 1920s. But how did it originate and what’s optical film sound all about?
What is Optical Film Sound Recording?
Optical film sound recording, unlike other types of sound recording formats, represents a unique need for the optical recording engineer to get the recording 100% right, 100% of the time.
Unlike other forms of film sound, optical sound recording cannot be re-recorded or otherwise corrected if a mistake or anomaly occurs. Optical sound represents a unique system in which a horizontal beam of light activates a photoelectric cell.
Which produces voltages that result in audio signals which are scanned to a photographic (optical) sound track on a film. An optical recorder, also known as a sound camera, then transfers the sound to an optical image.
This then can be used to produce audio signals that are amplified to operate screen speakers.
Advantages
Optical film sound has 1 key advantage over other forms of film sound. In that the sound is printed on the same film at the same time as the picture unlike magnetic film. Which requires two separate processes in order to print sound and visuals on the film.
Optical film sound recording continues to have a role in filmmaking even today, although it’s a bit different than what it once was.
As the focus on how to create optical film sound has evolved, today’s principal use of optical sound recording focuses more on creating a master optical negative which accompanies the final exhibition prints when all editing and instances of rerecording have already taken place.
Historic Types of Optical Film Sound
While commercial use of optical film sound would begin in the late 1920s. This technology would continue to be researched and improved upon for more than 100 years. In fact, researchers spent decades on learning, and improving, optical film sound recording techniques.
More than a dozen different optical sound formats have evolved from this research and focus in the past 100 years. Each optical film sound format would have unique benefits, and challenges, associated with it.
Historically, sound recording for film would begin in the early 1920s with the first feature film that included sound, The Jazz Singer, being released in theaters in 1927.
Check out this historic timeline of motion picture sound recording:
- 1930s Variable-Density & Variable-Area – The first optical film sound recording systems would become prevalent, representing photographic-sound recording.
- Late 1930s Variable-Area Tracks – The introduction of unilateral, bilateral, and dual bilateral variable-area tracks as well as push-pull tracks.
- 1940s Variable-Area Recording Favored – Variable area recordings had better output and greater sound level thus this became the chosen method of sound recording.
- 1941 Push-Pull Tracks on the Road. – Walt Disney’s Fantasia released with push-pull tracks in a roadshow operated by Disney technicians.
- 1955 Release of Oklahoma. – Double-width film that provided a great picture and six magnetic soundtracks.
- Early 1970s Magnetic Sound Becomes Less Popular. – CinemaScope would begin to lose popularity due to cost economics, researchers begin seeking cost-effective optical sound recording.
- Late 1970s theaters convert to Dolby. By 1979 over 900 theaters worldwide were equipped to reproduce Dolby-encoded SVA tracks.
- 1980s A Rise in Interest in Digital Sound. – Although monophonic photographic soundtracks (Academy Tracts), stereophonic photographic soundtracks, and magnetic soundtracks have their place, digital sound is gaining interest.
- 1990s A Rise in Cinema Digital Sound (CDS) – A Division of Eastman Kodak Company develops CDS, also recognized as surround sound.
In Essence
Through the years, optical film sound has certainly evolved with many formats being produced and some favored over others.
It all began with figuring out how to create optical film sound. Which would change the way we experience motion pictures and continues to impact our movie going experience.