Weak ground vs strong, solid ground (A/V application)

[CkRtech]

Hey All -

First post. Been dabbling in electronics since around 1999. I've also watched Dave for awhile and only now arrived here and registered. I imagine I have quite a few things I could ask, but the first will be this -

What sort of issues would you experience in analog video if your ground was say... a haphazard of cold solder joint with the absolute thinnest wire you could find vs a nice, thick wire with good connection to its two points? What sort of difference does it make?

Are you looking at something where the video signal either works or it doesn't, or can you have all sorts of things in-between? How is it manifested? Can you see what appears to be interference on the screen if your ground isn't as good as it could be?

Thanks!
CK