Late 80's VHS tape GREEN bright points & "stuck" light sources

[nicholasserra]

Thanks for looking. Hoping to get some answers on some weird VHS tape issues i'm seeing.

I've ran hundreds of VHS tapes through my current rig, and have yet to see issues like this. I've mostly ruled out the capture setup, so hoping to identify what might be on these tapes.

These tapes are all master tapes, shot on a "not so good" VHS camcorder in the late 80s. I'm seeing "stuck" light sources and trails, like light painting. Also seeing a lot of bright spots where they should be washed out white are coming through as neon green.

This shows up on both my refurb AG1980s (Deter and Tgrant), with TBC on or off. I thought maybe my capture card was going out, but then hooked up another VCR direct to a separate TV and also seeing the issue.

So the artifacts are 99% sure on the tapes themselves.

Looking for some reassurance that my capture setup isn't doing something weird here, and can then move on to post process fixing some of this.

Thanks!

Link to download raw capture sample (200mb):
https://nicholasserra-dropbox.s3.amazonaws.com/green-issue-sample.avi


[Attachment 62541 - Click to enlarge]

[Attachment 62542 - Click to enlarge]

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[Skiller]

This was a common sight on TV and home videos until the late 80's to early 90's. Your equipment is not malfunctioning. It happens because the camera used a so called pickup tube, a tube based image sensor with phosphor (such as Newvicon, Trinicon, Vidicon, Saticon and so on) rather than a solid state sensor. The principle is basically a CRT TV in reverse. An electron beam scans the phosphor which is hit by the light entering the lens. Anyways, the "comet" effect on bright light sources happens because they excite the phosphor so much that it does not stop glowing fast enough.
Also when the phosphor gets overexposed, color abnormalities like in your last two screenshots may happen but different types of pickup tubes reacted quite different to this.

[nicholasserra]

Awesome thank you for this confirmation. So basically i'm good to keep capturing, and i'll need to figure this out in post process.

Any common avisynth scripts or color correction patterns to correct this stuff? Not sure how much I can fix of the light trails. But maybe I can color correct the green spots back to white.

[Skiller]

Masking the green overexposed parts and color correcting them would be pretty feasible in a NLE but would likely require tweaking for each scene. Might be worth it though. Regarding the comet tails however I don't think they can be filtered because there is nothing to fill the gaps other than maybe interpolation guesswork which would look obnoxious I think. To be honest I quite like the effect, I wouldn't mind it at all. We are just not used to seeing it anymore these days. It's an old video, may just let it look old.

[lollo]

If the "comets" do not stay at the same place for many frames, you can give to FixRipsp2 a try (quite destructive)

[Skiller]

Maybe this video helps illustrating what the comet tails (streaking) looks like for those who are not familiar with it:

https://www.youtube.com/watch?v=sgPpbfC0gqk

(Mind you, this is a very extreme example.)