The fact that you notice the problem only when playing recorded tapes could show that you may have a camera, VTR deck, camera head, or viewfinder problem. First play this tape in an external VTR with a quality monitor. If it’s OK then the problem is not in the recording, but elsewhere in the system. At this point depending on how severe the problem is will determine what you do next. If you have the luxury of a similar model camcorder or dockable, start swapping viewfinder, camera head and VTR, if applicable.

Moving components around helps narrow down where the problem is and helps reduce maintenance costs. If the problem follows the viewfinder for example, then it’s possible to replace the viewfinder or just send it in for repair instead of the entire rig.

Often the above problems are caused by aging capacitors in the viewfinder, camera head or VTR playback circuits. I would keep an eye on the problem and then get service when it gets worse.