Is this scan line normal?

[spinsky]

I have what looks like an artifact/bad scan line on all my captures?

At first I didn't really notice it, but if I mess with the chrominance on my A to D Black Magic Design box, it becomes obvious (and still visible when not adjusted up or down).

To me it looks like its in the active video area, a couple lines below the first 1/2 active video scan line (I can't tell if its just one line or two across frames). Could it be part of the vertical blanking interval or is it just typical and I'm overanalyzing? Also visible on the VCR blue screen, no tape/content playing. Starting to wrap my head around the NTSC spec but would appreciate any explanation here. I was under the impression that all active video scan lines are untouched in the sense that any vertical or horizontal blanking is above below left or right of the image which is why this line confuses me.

Capture setup (Video8):
(Sony EV-S3000 -- BMD Analog(s-vid) to SDI -- BMD SDI to Thunderbolt capture)
Ignore the CC lines - this is my test tape (new unopened - until recently), The Naked Gun on Video8, this happens on home movies too.

Thanks

[latreche34]

Hook up the VCR to a TV with just scan feature (no overscan) and see if it's there, otherwise it is generated by your capture hardware.

[spinsky]

Hooked up to my tv and minimized the overscan but wasn't enough to see it. I don't have any CRTs laying around, certainly not nice ones. If I plug in a VHS VCR to my capture setup I don't see the same line, this makes me think it's the Video8 VCR.

Assuming it is the Video8 VCR, still curious to know what it could be from a signal or hardware standpoint.

[aramkolt]

I'd almost have to guess that's baked into the actual recording if it's in the exact same place every time - particularly also if you don't see that line with other Video8 tapes played on the same machine. Not sure how you'd prove it other than putting in in a different Video8 player and if you see it on a different player too, then definitely would be the tape itself I think.

[spinsky]

I see on any tape (most of my tapes are from my Video8 Camcorder but I also have the copy of that movie purchased new). Unfortunately my video8 camcorder is dead at the moment, so can't easily get a second Video8 source.

I reached out to the seller I bought the deck from, a credible source (on Ebay).
They are claiming the following:

Quote:

That area you are pointing is where sync pulses such as (vertical, horizontal / hammer head, including color burst or chromatic sync reference) regenerated by editing devices (time base correction) or inherent to composite signal can be seen during editing and ignored or hidden by viewing devices after editing.

I don't really buy it but im not sure. Seems like what they are mentioning should be in the non-active video area, not a few lines down. I am not claiming to be an expert at all, but I've been reading the NTSC spec for hours and can't wrap my head around what that could be from a signal standpoint (hence reaching out for second opinions). I also don't want to rely on overscan to "fix" it.

First image I attached shows the active video content extends above the line, while this one will show it more or less unobstructed. You can also clearly see a few blank lines, closed captions data, and the first video 1/2 scan line and more before it gets to this line.

TestImageLine.jpeg

[latreche34]

The TV does not have to be CRT, any TV with just scan, If you see the line, it could either be the tape or the player itself, If you don't see it it is generated by your capture hardware, Connecting another VCR to the capture hardware does not necessarily means it is not faulty, capture cards and software react differently to different analog devices.
Another test you can do, if you pause the frame and go step by step with the video player, how does that line behaves, does it freeze and move frame by frame? If so, it is the tape.

[spinsky]

My tv has composite in - tried that but it's over scanning, naturally, and only has ±1 control to change that. So technically this line is obstructed if present and I am not able to expand that option to under scan ignorer to see it.

The line itself looks to show the proper image, just the luma is totally out of wack. If I adjust my analog to sdi converter box luma setting it exasperates the problem, going completely black or white depending on the adjustment slider extremes. If I leave it at 0 gain it's ok, but still it's distinctly off compared to surrounding lines.

So ultimately, I don't think it's the tape - it also shows up on the VCR blue screen/menu with no tape. Based off trying another VCR (not a great test since I couldn't get the VCR to play a VHS), the line wasn't there. Leads me to believe it's the Video8 VCR.

[latreche34]

If it's in the VCR's menu this definitely rules out the tape.

[spinsky]

Yeah, fortunately I think so, at least the tapes are good. If the deck is bad on this line it will bug me, but don't know if it's worth fixing (if possible) or worrying about. still need to rule out the capture equipment, certainly possible its that.