Film - A Practical Guide to Video and Audio Compression - page 67

4.13 Ingest and Restoration

Any currently existing movie film from the 8mm era is likely to have faded. After scan-
ning this material in, at least some color correction is going to be necessary to get the best
result. Modern compression software provides this. Software like Final Cut Pro or Premier
will work from the raw, uncorrected footage if necessary. Their built-in color-correction
capabilities can be used during the editing session. Of course, this color correction is
unnecessary for black and white film. However, contrast enhancement will be required to
eliminate over- or underexposure.

4.13.1 Spliced Joints

There will be significant problems with spliced joints in this old material. The older stock
was spliced with acetone glue that welded the two parts together. The same is true for any
Supersound stripe that was attached to the film. Later materials were based on a polyester
substrate, and during the 1970s various alternatives using short pieces of transparent tape
were tried because there were no readily available solvents for polyester at the time.
Significant cleanup and restorative attention will be necessary. When handling archive
material, the telecine process must be very kind to the film and not cause it to be twisted
or bent around tight pulleys and sprockets more than necessary. Modern transports carry
the film gently and steadily through the scanning area with a smooth and flowing motion.
This avoids damage due to the stop/start jerking movement that a projector has to deploy.
Figures 4-21 to 4-23 show a cross-sectional view of the film to illustrate some of the
splicing techniques you will encounter when digitizing old film stock. The beveled-edge
splice is quite weak and will break when the glue deteriorates. If this splice is done care-
fully at the frame boundaries, it is hard to detect in the projected image.
The undercut splice is stronger but damages a larger area of the film. In fact, it tends
to completely ruin a frame of 8mm film. It is less likely to break due to the glue, but the
film is quite weak at the ends of the joint.

Figure 4-21 Bevel edge butted and glued splice.

Figure 4-22 Undercut overlap glued splice.

Figure 4-23 Adhesive taped splice.