Jumping picture

[Mr Chris]

Right, proper newbie question here as I'm unsure of the terminology I need to use to describe the issue...

I'm capturing from VHS - sometimes to a DVD recorder, sometimes to PC - and every so often the picture jumps up and down. Nothing major: usually just a single field by a couple of pixels. What's this called? "Jitter"? Some tapes are considerably worse than others, with loads of these jumps in a short space of time, or even consecutive fields being off by those two pixels for extended periods. (How's that for a cumbersome description?)

Anyway, what do I need to stabilise the picture? Am I describing exactly what a time base corrector fixes? Or do I need something else? Any sort of recommendations at a consumer price point (i.e. best budget models) that will help me to get more stable captures will be greatly appreciated.

[LMotlow]

Anyway, what do I need to stabilise the picture?

A line-level tbc.

Am I describing exactly what a time base corrector fixes?

You mostly described the kind of problem a line-level tbc addresses.

Or do I need something else?

If you also have missing or dropped frames or bad audio sync, you also need a full frame tbc.

Any sort of recommendations at a consumer price point (i.e. best budget models) that will help me to get more stable captures will be greatly appreciated.

You won't' find an external line-level tbc at a consumer price point, but there are used frame sync tbc's for around $200 to $500 USD, or more if you like to boast. For scanline sync you'd need a prosumer VCR from JVC or Panasonic that has a line tbc built-in. Or you can get by cheaper with something almost as good, like one or two legacy DVR's that can be used as a passthru TBC. https://forum.videohelp.com/threads/319420-Who-uses-a-DVD-recorder-as-a-line-TBC-and-what-do-you-use

If you have these problems recording directly to DVD, you'd better start with a decent VCR and a better DVD recorder.

[jagabo]

By the way, you usually see that vertical jitter with VHS tapes recorded in LP or SLP mode (and multi-generation copies). S-VHS decks with line TBCs usually don't play those tapes well. So a DVD recorder with line TBC works best for those. A line TBC will also clean up horizontal jitter, another big problem with VHS tapes.

[LMotlow]

I think you mean that LP/SLP plays crappy on anything made by JVC, who never catered to slow VHS the way Panasonic or SONY did . To get better playback from those, use a Panny. Better off with something like one of the Panny VS-S4670 series or the slightly later AG business-oriented SVHS machines without tbc fom the late 90's, then feed playback thru a pass-thru Like ES10 or ES15. Slow tapes played on cheap players via composite cable, regardless of brand, will look like crap no matter what's used for a tbc.

[Mr Chris]

Thank you both very much for your help. Your replies at the very least gave me some terminology to Google, which has put me on the road to being able to understand the subject more fully, but...

Anyway, what do I need to stabilise the picture?

A line-level tbc.

Am I describing exactly what a time base corrector fixes?

You mostly described the kind of problem a line-level tbc addresses.

Why line-level? Reading the difference between the two here:

http://www.digitalfaq.com/forum/video-restore/2251-tbc-time-base.html

it clearly states that an "S-VHS VCR Line TBC" will "NOT help much with vertical "picture bounce" jitter -- in fact it can sometimes increase the amount of jitter". On the other hand, a "Standalone, External Full-Frame TBC" will "reduce visual on-screen image jitter (mild up/down image bounce)" - which sounds precisely like the issue I described in my original post.

Have I read all this incorrectly? Because this seems to be conflicting advice to me.