Demonstration of Phonofilm Assures Speaking Movies/Do It in Technicolor -- January 26, 2023

Washington Evening Star, 05-January-1924

Lee De Forest, a pioneer in vacuum tubes and radio, introduced his Phonofilm sound-on-film picture process in 1923.

Demonstration of Phonofilm

Assures Speaking Movies

By the Associated Press
CLEVELAND. Ohio. January 5. -- The phonofilm, a combination of radio and motion pictures, the invention of Dr. Lee De Forest, has been demonstrated successfully, according to those who have heard and seen the talking pictures. It is his object to produce motion pictures in which the characters speak. Dr. De Forest gives this explanation of the process:

"In the studio a motion picture is taken in the usual manner, but in addition to tbe camera lens, which registers action, a microphone registers every sound made by the actor. A wire from the microphone passes through an audion amplifier to a gas-filled tube, called the photion, located in the camera. The light from this tube fluctuates in exact accordance with the amplified telephonic currents which originates from the actor's lips.

Sound Waves Photographed.

"A very line slit is located near the negative film, through which these fluctuating light rays are registered on the sensitive emulsion of the negative as fine lines which are actual photographic sound waves and, being on the same film as the picture, insure perfect synchronism at all times.

"A positive print then is made in the usual manner. In reproducing, a small attachment is placed on the standard motion picture machine. This attachment contains a small incandescent lamp, which is placed in front of the photographed sound waves on the films. This light, passing through the sound record, falls upon a photo-electric cell, its brilliancy being governed by the density of the photographed sound waves. The photo-electric cell’s electrical resistance at any instant is determined by the amount of light falling upon it.

Synchronize Sound and Sight.

"The telephonic current from the cell then is passed through the audion amplifier, where it is built up hundreds of thousands of times. Thus, the actor's words are converted into telephonic currents, amplified, photographically registered on the film and eventually transformed back again into telephonic currents, which are made audible by the loud speaker.

"As the motion picture must be projected upon a screen to be viewed, it is likewise necessary to project the sound, in order that it may appear to come from the actor's lips. This is done simply by running a lamp cord from the machine to the screen, where a loudspeaker is attached."

Motion Picture News, 05-January-1924

The use of Technicolor as an extra in feature films was growing. In Cecil B DeMille's Ten Commandments, the Biblical prologue was shot in Technicolor. 

Motion Picture News, 05-January-1924

Paramount announced that its first color film would be an adaption of Zane Grey's novel Wanderer of the Wasteland. 

Film Daily, 10-January-1924

"Do it in Technicolor."