To transfer VHS to DVD properly, it is important to optimize the video signal before digitizing it. This can be achieved by using good playback equipment, the best video connections, and signal correction devices.
The most fundamental part of digitizing VHS or other type of analog video is the playing of the tape. If the tape plays poorly, then the signal being fed to the digitizing device will be poor and the final digital video product, whether a DVD or other digital video format, will also be poor. Just because the video is being transferred to a DVD does not necessarily mean it will be comparable to the typical DVD quality. There is an old saying in the video digitization field – “Garbage in, means garbage out.”
A good quality video cassette recorder should be used to transfer VHS to DVD. Avoid using cheap equipment. The equipment must also be clean and the internal tape guiding system properly aligned. If the VCR is not performing properly or has been used extensively, then it is a good idea to get it professionally cleaned and serviced before beginning the transfer process. It may be a good idea to purchase a new VCR, although nowadays it is getting harder to find stand alone VCRs, let alone good quality ones. At the very least, use the newest and/or best unit that is available.
If possible use a S-VHS machine or pro type VCR. These upper end units will allow for better output video connections than standard consumer video cassette recorders can provide.
Basically, for VHS VCRs the options are composite or S-Video. If a playback unit is available that has the S-Video output, then use this option. Otherwise, the composite outputs must be used. This is explained in more detail at the following link.
Signal Correction or Adjustments
Another important step to transfer VHS to DVD or to any other digital video format is signal correction. The most basic adjustment that can be made on any VCR is tracking. Play a small portion of the videotape to be digitized and adjust the tracking button (usually on the remote) by pressing the up or down direction in order to clear the picture from waviness or horizontal lines on the screen. If the adjustment is being made in the wrong direction, it will be obvious as the picture quality will degrade significantly. Video tracking adjustments may or may not be necessary but will be determined when a sample of the video is played and examined.
Higher end VCRs may provide internal time base correction (TBC) which eliminates problems in the video signal by: making adjustments to the technical parameters of the signal (voltage, horizontal phase, chroma phase, etc.); synchronizing video parameters with other equipment; and correcting various defects in the video signal. External time base correctors can also be used that perform the same functions as internal ones. The video from the VCR is fed into the TBC prior to going to the digitization device.
In addition, in the transfer VHS to DVD process, more corrections or adjustments to the outputted video signal can be made using a waveform monitor or vectorscope. These devices can be software based or hardware based. Knowledge of the proper use of these devices is critical, otherwise more harm than good will occur to the video signal. Generally, these types of devices are only used in higher end transfers because of the cost of the software/equipment and the expertise required to fully understand how to use them. For the average transfer job, tracking correction and time base correction is usually all that is required to get a reasonable quality output video signal that will be fed to the digitization device.
Other VHS transfer information: