I've used the Panasonic AG-1980 for years--it's a great machine. But recently I started noticing a problem: when the TBC is engaged, the unit occasionally causes a thick vertical stripe to appear down the left side of the picture. This stripe is cut off as overscan, which is why I didn't see it for a long time with my DVD recorder-TV setup. I finally spotted it when I ran a bunch of VHS-C tapes into my computer. Here's what it looks like:
The stripe appears down the left side of the picture. It appears to be part of the image, but shifted--you can see how the curb doesn't line up in this example. I believe the stripe is a leftover image from the previous frame, because of situations like this:
The above image was taken from the first frame after a jump cut. The stripe is clearly the image from the previous frame. (I have verified this on other jump cuts as well.)
Here are a few facts regarding this error:
- The Panny's line TBC is the culprit. When it is turned off, the stripe is 100% gone.
- I have tested this phenomenon with more than one Panasonic AG-1980. All displayed the problem on the same tapes.
- The stripe only happens with SP tapes. I do not recall seeing it on EP tapes.
- When the camera is still, the stripe is gone. It appears most often when the camcorder pans from one side to the other, or whenever the camcorder is moving around quickly (it was hard to find a screenshot that wasn't blurry, for this reason).
- Not all tapes show the problem. I transferred a bunch of tapes recorded by the same camcorder, and about half of them showed the stripe. Some were much worse than others. And some tapes in the same collection didn't display the stripe at all. Then I transferred tapes recorded by a different camcorder, and only spotted the problem on about five frames in 30 tapes (all frames in which the camcorder was bouncing around wildly). So depending on the tape, the error ranges from a stripe that you can easily see to an occasional single-frame error that 99.9% of viewers would never spot.
My conclusion is that the Panny's line TBC is a frame behind within this vertical stripe. This would explain why the error is more apparent on scenes with fast motion or on jump cuts (where the frames are very different from one to the next). But it must be more sensitive on certain tapes as compared with others, and I definitely can't figure out why SP is so much worse than EP.
I am here because I know of no one better to address this problem than digitalFAQ.
1) What is your assessment regarding why this error is occurring?
2) Should I just turn off the TBC on SP tapes? My inclination is to leave it on (the capture is usually more stable and smoother), but spotting frames with these stripes is very hard to do during capture. It bothers me a lot that such a valuable tool on this good VCR can't be used without an error potentially occurring.
3) Hasn't anyone ever seen this error before? I've caught it with a variety of tapes on a few units, so I can't believe that folks who capture to the computer and do more editing than I do haven't noticed this. But I can't find anything online about it.
Thanks in advance for your insight!