Is this sharpening noise halo, ring?
 

Is the black line above the lawn chairs considered Halo, Ring, or something else? Which Vapoursynth tool in Hybrid would work best to minimize it?

This is luma edge over sharpening, Try to reduce it at the source, What's the capture workflow, the software and the video formats involved?

Hmm. That's kind of doing what a couple of my SDI capture devices were doing. I always assumed it was either baked into the tape itself and sort of a consequence of high contrast edges.

Just as an example of what I was seeing in one of my tests below. You'll notice the ring on her finger and her nose seem to have too much luminance on the left, but is also much sharper on the left in general. You can see a shadow to the right of her face and to the right of the coffee cup. Text also seems to have a shadow and more sharpening noise on the left, yet I still prefer the left. The one on the left is a BMD mini Analog to SDI converter and the one on the right as an ADVC-G1 both of which convert to SDI. Both were fed component from a FA-310 Frame TBC. Playback source is a 9911U (with TBC on) with a commercially made SP tape outputting S-Video into the TBC. The actual luminance levels going into both devices was adjusted via proc amp and waveform monitor so as not to exceed 100IRE. Both devices use Analog Devices DACs with slightly different part numbers.

I'm kind of shocked that there's so much more apparent detail in the hair in the left. Also noticed that the frames aren't identical (Johny Carson's hand is in a different position in each), so could be the ring was just that way in that specific frame.

But more to the OP's point, how do you reduce luma sharpening at the source? I'm not aware of most VCRs having much in the way of sharpness adjustment - or are you saying choose "EDIT" mode if available?

Attachment 17783

Avoid unnecessary conversions, If SDI is your digital port try to digitize directly from Y-C to SDI, any intermediate steps like Y-C to component and adding pieces of equipment in between will degrade the quality. Also the BMD mini Analog to SDI converter is not recommended for analog capture.

Yes, use edit in VCR and avoid sharpening in the capturing software.

The effects can be anywhere along the path. Recording time, playback gear, capture card, wiring, settings therein. Some are baked in, some are added by bad/wrong/cheap gear.

Different frames cannot be compared to this granularity. Something as simple as light source direction can vastly change shadow, which is where most detail originates.

Source: 8mm tape recorded with RCA Pro820 (built 1990)

Sony TRV-66 (tbc and dnr on) > ES-15 > DVK-200 > AIW 9600XT > VDub1911 > Hybrid