Video8 (Hi8) playback problem (black bars coming and going)

[pumabr]

Well , I have a problem that I think can be very simple or very complicated. I have with me 16 * 8mm video tapes with 5-10 years of two friends of mine. The aim is to transfer the video to digital format. Some tapes playback smoothly, but in other tapes the image is displayed with a black bar that appears at the bottom of the image and go to the top. This problem happens every second, affect the audio too, and this is common to all the tapes that are not playing correctly. I put a video on this link to better demonstrate the problem:

http://youtu.be/Li5J4EgRxXw

In the first 33 seconds is the playback of a problematic tape, recorded many years ago in a Sony CCD-TR750E camcorder. After that I changed the tape and put another who does not have this problem. This second tape was recorded on a Samsung VP-L800 (which no longer works). I played this tapes in the Sony CCD-TR750E , therefore, in the same camcorder that recorded the tape with the problem.

I've playback the problematic tapes in 3 different camcorders, and even in a Hi8 deck, but the problem remains always the same.

I don't know what could be causing this playback problem. I've searched on google about it but found nothing regarding this problem specifically. I don't know even how this problem is called... does not seem to be an tracking issue since I've even tried adjusting the two spanner slotted screws where the tape passes, but without success. Some help, please ?

[zoobie]

It looks pretty bad. There may be a slight window to grab a still or two. Perhaps these tapes were exposed to a weak magnetic field at a certain point.

[pumabr]

I really have no idea. But it is not strange that these flaws in the image are so linear? The tape is in good condition... and if the problem were derived from exposure to a magnetic field, should not another type of anomaly appears in the image, like noise or distortion?

[zoobie]

It reminds me of my brothers 8mm when he went thru an airport metal detector. All of his tapes were ruined and similar to yours.
You could take a test tape and try waving a magnet near it at varying distances and see for yourself what anomalies happen.

[NJRoadfan]

Does it only happen on certain recorded segments or on certain positions of the tape? (usually the first few foot of tape on each end of the spool gets beat up pretty bad)

I have encountered VHS tapes where a recorded segment in the center of the tape had poor tracking/video. It was likely due to a "misload" of the tape by the camcorder's transport. The tape was incorrectly threaded around the drum that one particular time the cassette was loaded into the camcorder.

The other problem is usually within the first few minutes of a tape or at the very end. The leader is exposed to the elements and tends to get beat up by constant threading/unthreading of the tape. The pros avoided this by recording a few minutes of leader using color bars and tone. You can occasionally fix some playback issues by "repacking" a tape by fast forwarding it to the end and rewinding back to the beginning a few times.

[pumabr]

I asked the owners of the tapes where they kept the tapes. One stored the tapes for about 2 years in a drawer below a CRT television, and the other in a cabinet kept away from any magnetic field. None traveled by plane with the tapes. So I think that this problem isn't derived from exposure to a magnetic field. But obviously there is no absolute certainty about it

Happens throughout all the tape, from start to finish! And this problem is constant and equal over the entire tape. I suspect that the problem is related to the camcorder's transport, as NJRoadfan sayed. But it's strange to me because I have the camcorder that recorded the tapes of one of my friends, and these tapes now playback with this problem! And he has almost absolute certainty that this camera was never refurbished.

Is there any way to tune the camcorder's transport mechanisms so that it is possible to read these tapes smoothly?

[smrpix]

The regularity of artifact you're seeing suggests it could be gunk or a hair on the record head when the recording was made. Also, FWIW "below a CRT television" is a good place to encounter a magnetic field, but I don't think that's the issue here.

Or another thought -- were any of these recorded in LP mode? In which case a timing/tension adjustment could make a difference.

[pumabr]

I don't believe the problem was dirt in the record head, because these tapes have played without problems spawned years ago! I also find it unlikely that the problem is related to magnetic fields.

All tapes are recorded in SP mode.

I tryed the "repacking" technic (FF the tape to the end and REW to the beginning a few times) with one tape, and the result was that the tape left to show picture at all! What is going on here?