In PAL and SECAM video standards used in Europe, film is shot at 25 frames per second (fps) and video is 25 fps, which creates a 1:1 ratio; one frame of film converts to one frame of video. In the United States, NTSC is the film and video standard, which shoots film at 24 fps and video at 29.97 fps.
To overcome the difference in frames per second when converting film to video, the pulldown process is used. This term refers to the pulling down of the shutter on a camera and holding it before the next frame of film pulls down, correcting the rate of speed from 24 fps to 29.97 fps.
There are several methods to convert film to video. One process is the cathode-ray tube (CRT), which projects a beam of light onto film as it passes through a scanner. A charged-coupled digital device (CCD) reads the images. A film chain can also be used to make film-to-video conversions. The film chain is a film projector that projects the image directly into a video camera.
The transfer from film to video involves two categories: video dailies and final transfers. Video dailies are made with the intent to go back to the film negative. Final transfers prepare for the finalizing of the edited film.
Before finalizing the process, the filmmaker instructs the facility on certain specifications that must be done before the project is completed. Some of the most important ones are color correction, audio syncing and time coding.
Color correction is the most important function during the telecine process, and the process determines how the project will look. Color correction can be expensive, and the number of hours required for the transfer increases with a detailed correction of the film; it can take up to 15 to 20 times the running time of the actual footage.
When transferring audio from film, you must consider the rate of speed of the audio. The audio must be pulled down by a rate of 0.1 percent to match the speed of the video. The telecine process actually runs at a rate of 23.976, so the audio needs to be slowed by 0.1 percent.
A non-drop timecode is a continuous system used for editing. Adding timecode along with picture and sound enables the transfer facility to easily locate footage. Some telecines can easily read the timecode from the video and the audio and match them automatically, syncing the film and sound.
The post-production process of converting film to video is a detailed and complex process. Ask other filmmakers about post-production facilities and how to get the best results from the telecine process. Work closely with the facility to prepare your transfer to get the desired result for your project.