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Film Transfer to DVD Flicker or “Rolling Bar” Considerations


March 11, 2011 by admin

In generations gone past family memories were captured to motion pictures with regular 8mm, Super 8mm, and 16mm film. In later years sound film started to gain use. The means to view these family treasures have for the most part vanished from common availability. Consequently these films have in many cases been sitting in closets becoming forgotten memories and degrading with age each year. There are many service providers that will transfer these family legacy memories to modern media with varying degrees of excellent quality.

At W. Cardone Productions we recommend that you try different providers with sample reels and then evaluate the results before selecting one to transfer your entire collection. While there are a number of excellent providers, there are those that you will be disappointed with. We make this especially easy for you in that we will transfer one 3” reel (50 feet) of your regular 8mm, Super 8mm, Super 8mm sound, 16mm, and 16mm sound (magnetic or optical) for free so that you can evaluate our results for yourself.

Presented herein are a few considerations to look at relating to the quality of home movie film converted and transferred to DVD. As you will see, many issues exist which the average consumer will not have thought of. These issues can have a dramatic effect on the overall quality that is delivered to you and therefore passed on to generations even yet unborn.

In this first installment we will examine flicker. From time to time we will add additional posts relating to the quality of film transferred to modern media.

Flicker is probably one of the most prominent issues relating to regular 8mm and Super 8mm film transferred to DVD. But it is not a flicker from the film itself. The flicker that we will address here is a “telecine” issue.

The flicker that most people think about with film is from a slow frame rate. The human eye has a “persistence” characteristic that makes it possible for film and even modern television to create the illusion of motion. Regular 8mm home movie film originally shot at 16 frames per second (fps) and then shown at that same speed will usually show flicker from the inability of the human eye to maintain a persistence from each advancing frame. Regular 8mm and Super 8mm home movie film shot at 18 fps and projected at that same speed will usually appear to be flicker free having a nice fluid motion perceived by the viewer. However, if telecining is not addressed in its transfer to DVD, a flicker or “rolling bar” will be observed on the TV even though the projected image it was taken from was very pleasing to look at with its fluid motion.

The problem is that the film is being projected at 18-24 fps while the television or computer monitor is scanning at 30 fps. A miss-match results which is perceived by the viewer as a rolling bar that falls or rises across the screen as the clip proceeds. Sometimes the rolling bar is faint and the viewer detects it as a faint pulsation. Other times it is dramatic, clearly showing as a bar that keeps rolling down the screen.

With regular 8mm and Super 8mm films this can be easily dialed out by merely slightly adjusting the speed of the film projection until the motion is fluid. Dialing in a speed too low or too high will result in a rolling bar either way. That “null” spot must be found. However, the rolling bar is not detectable until the film has been captured and then shown on a television. The camcorder capturing the projection will not show it since its viewfinder scan rate is unrelated to the NTSC television standard.

With Super 8mm sound film we have less flexibility. Manufacturers of the Super 8mm sound film cameras had very loose standards to enable low price entry points and consequently the speeds the films were shot at are not precisely known. When transferring Super 8mm sound film we would like to dial in a film speed where the voices sound normal. However, if this results in a rolling bar then we have to go to Plan B where we dial in a speed that nulls the rolling bar since a rolling bar cannot be taken out by even exotic means once captured to digital media. With Plan B we then correct the pitch of the voices in the digital media after the capture is complete.

There is another means which exists to deal with the telecine issue whereby the rolling bar is not nulled but is simply eliminated. This can be done if a 5-blade projector is used to project the image for capture. The trade-off with this method though is that it cuts down on the projected image brightness too much. The camcorder will then try to compensate by increasing its video gain which adds grain to the television image. Video gain which causes grain will be the subject of another post on the quality of film transferred to modern media.

Please look for additional posts where we will discuss still other considerations relating to home movie film conversion and transfer to DVD. And also please remember that at W. Cardone Productions we are among the top service providers treating your family treasures with the respect they deserve.


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