archiving old VHS tapes

[Andy Prada]

This is such a difficult issue to deal with because there are so many variations as to possible cause and effect. Quite frankly, given the fragility of the magnetic recording medium and the way a lot of it is stored I’m amazed most of it lasts as long as it does.

I too had similar problems (CS4) with an old VHS tape that I needed to capture, edit and encode for DVD.

One thing you do need is time because you may have to capture the material in lots of little chunks and stitch it together – bit like a quilt.

The lines you talk of may be damaged tape due to accident, or partial erasure of the RF signal. We used to talk of signal to noise ratio back in the old days. A high signal to noise ration meant good pictures or signal strength recorded to the magnetic medium (more video – less speckles or snow!) You get the same result on an analogue TV when your aerial isn’t plugged in properly.

VHS media will degrade over time – especially when it is not stored optimally. I have VHS tapes of programmes I have made that are simply not as clear as when I first made them.

Back to partial erasure this could be caused by say: storage next to electrical devices, acute variations of temperature over a long period – there are all sorts of potential causes. A TBC will stabilise but will not cure poor signal to noise on a tape. Most TBCs will sharpen or soften the core but I don’t think this is your problem

Presuming that you have tried it on a few VHS players (so it’s not your own machine causing the problem) Boris BCC6 has a DV fixer software filter that can remove jaggies from video and a range of stuff that can clean up a picture. I’m sure other companies have similar stuff.

You could try deinterlacing and choosing to play only one of the two fields on offer. Because VHS is helically scanned video – recorded at an acute angle onto the tape field by field – you might have some luck with this. If the tape was recorded on a damaged machine this sometimes solves the problem.

If none of this works you may have to resort to adding a caption DAMAGED VIDEO to ensure people don’t think it’s you fault.

Perhaps if you could post a few jpegs as an example I could offer other thoughts.

best

andy

[Pushpanatha De silva]

Try following:

1. Try cleaning video heads and rollers with Iso propyl alcohol leave it to dry..

2. Use Canopus ADVC 300 to convert Analog to Digital with colour correction facility

3. Use pro quality audio/video cables

[Tony Breen]

Thanks for responding. Have already used suggestions 1 & 3. The damage has been caused by poor storage, so I had hoped that there would be a filter to cope with this. The footage is .avi so it might be a matter of scanning frame A for dropout(horizontal white line) and cloning the info. from frame B and pasting.

Antoin151

[Tony Breen]

Thanks for the info Andy. I believe poor storage is the cause. I took down some tapes from the attic last Nov. and they were OK. After the worst winter in living memory, I took down the present group.
I see a long period of “stitching” before me.
I never thought of the deinterlacing method.
Thanks again.

Antoin151

[Jim Arco]

…just to add my two-cents worth…

If the lines you describe are dropouts – white lines with no picture information at all – the tool you are looking for is called a drop-out compensator. Pro level tape decks included these as an option. They were available on some high-end VHS decks.

You could try using a second video copy below the main video. Use luma keying on the top layer to detect the white lines; blur the lower layer and/or offset it a few line vertically.

The blue screen problem is probably caused by the tape deck thinking that the noise is a copy protection technique. Also, playing damaged video on VHS decks with TBC sometimes makes the video worse. The noise on the tape can fool the TBC to generate sync pulses at the wrong time, resulting in jitter or roll. You may want to switch off the TBC or try a different player.

All of this is from the Library of Ancient Video History; your mileage may vary.

[Tony Breen]

This was a very helpful contribution. I was convinced that poor storage was the problem. However, I have found that the quality of the tape has a lot to do with survival. I used TDK S-VHS for my work and the tapes have weathered reasonably well. Earlier tapes would have been VHS and I suspect of poor quality.
I wonder do they sell drop out compensators separately. Thanks again

Antoin151