In this video, i have explained Optical Recording on Films in Audio and Video Engineering, Television Engineering with following timecodes:

0:00 - Audio Video System / Television Engineering Lecture Series
0:18 - Outlines of Optical Recording on Film
1:19 - Types of Optical Recording
3:30 - Methods of Optical Recording on Films
3:56 - Variable Density Method to record sound on films
8:06 - Variable Area Method to record sound on films
11:19 - Reproduction of sound from recorded film

Following points are covered in this video:

0. Optical Recording
1. Optical Recording on Film
2. Types of Optical Recording
3. Methods of Optical Recording on Films
4. Variable Density Method to record sound on films
5. Variable Area Method to record sound on films
6. Reproduction of sound from recorded film

Engineering Funda channel is all about Engineering and Technology. Here this video is a part of Audio and Video Engineering, Television Engineering.

#OpticalRecordingonFilm, #TypesofOpticalRecording, #MethodsofOpticalRecordingonFilms, #VariableDensityMethodtorecordsoundonfilms, #AudioandVideoSystem, #TelevisonEngineering

Details of Optical Recording on Films, Types of Optical Recording, Variable Density Method to record sound:

Optical recording on film is a method of recording sound on photographic film, which was widely used in the early days of motion pictures. There are two main types of optical recording: variable area and variable density.

Variable area recording is a method in which the amplitude of the sound wave is directly translated into variations in the width of a slit on the film. As the sound wave amplitude increases, the width of the slit also increases, creating a corresponding change in the amount of light that passes through the slit. This change in light is then captured on the film as a visible waveform.

Variable density recording, on the other hand, is a method in which the amplitude of the sound wave is translated into variations in the density of the film's emulsion. As the sound wave amplitude increases, the density of the emulsion also increases, creating a corresponding change in the amount of light that is absorbed by the film. This change in light is then captured on the film as a visible waveform.

The variable density method is considered to be the more accurate of the two methods, as it allows for a greater dynamic range and better signal-to-noise ratio. In addition, the variable density method can also be used to record multiple soundtracks on the same piece of film, as each soundtrack can be recorded at a different density.

One common method used in variable density optical recording is the "Westrex" system, which was developed by Western Electric and used in many early sound-on-film systems. In this system, a carbon microphone is used to capture the sound wave, which is then amplified and used to modulate the intensity of a beam of light. This modulated light is then focused onto the film, where it creates a varying density pattern that corresponds to the original sound wave.

In summary, optical recording on film was an important technology in the early days of motion pictures, and both variable area and variable density methods were used to record sound. The variable density method, in particular, allowed for a greater dynamic range and better signal-to-noise ratio, and was commonly used in the Westrex system and other early sound-on-film systems.