Quality difference between DV and S-Video outputs

[mkd8919]

Hi Everyone. I’ve been capturing some old home VHS recordings but I’m now questioning my method. I’m using a JVC SR-VS30 S-VHS Deck. This deck will output regular VHS to DV. It also has Digital TBC / NR and a Video Stabilizer built in, which are both enabled. Until now I’ve been capturing VHS using the DV out on the deck. I’ve been capturing DV using WinDV. However, I noticed that the image on the TV I had connected to the deck with s-video seemed to have darker blacks. Also the DV output does not have the messages about video calibration, the play / pause screen, the menus etc. I have a Hauppauge Impact-VCBe and tried capturing with that using WinTV8 (defualt settings) and the s-video. I’ve taken screenshots from both, and the s-video capture seems to be darker. What I’m unsure of is whether or not that is better. Would the DV capture be more accurate? I noticed in things like ads with white lettering on a black screen, through DV the background is grey, whereas with the s-video it’s much closer to black. From the screenshots and playback, I can't really see a difference in quality, other than the s-video output seems to be darker, and areas that are supposed to be dark seem somewhat washed out through the DV.

Screenshots (taken through VLC)
S-video capture:
[Attachment 45167 - Click to enlarge]
DV capture:
[Attachment 45168 - Click to enlarge]

[nick1977]

I'm no expert at this sort of thing (I'm sure one will be around soon!) but the definition looks better in the DV capture. You can see this by zooming on the front door frame on the closest car. The DV capture does look a bit washed out, but the S-video capture looks like the whites and blacks are blown out a bit. A natural image is somewhere between the two, so I would suggest using the DV capture and adjusting levels / brightness etc.

[jjeff]

Personally I think the first, darker(S-video) image looks best the second DV image looks like an IRE mismatch.
Digital has a IRE black level of 0 while N. American analog SD(which includes composite and S-video) is +7.5 IRE. If capturing a 0 IRE signal with a SD recorder, when you play back the image it will look washed out, like your second image.
I don't know if DV is 0 IRE but if it is and you're capturing it with a device looking for +7.5 IRE, you'll end up with that washed out looking video. The resolution might be better but to me a washed out picture is too steep a price to pay for a little resolution

[jagabo]

DV (especially from camcorders) often has both black and white levels too high. Instead of blacks at Y=16 and whites at Y=235, blacks are around 32 and whites around 255. You can easily adjust for this in post. But any brights that would have gone above Y=255 can't be restored. Your s-video cap appears to have more standard levels.

If you're DV converter has an IRE setting set it to North American NTSC (7.5 IRE setup), not Japanese NTSC (0.0 setup).

[kodec]

You can have the TBC AND the stabilizer enabled at the same time on that VCR, really? That's great, on my JVC S-VHS VCR one option shuts off the other automatically, e.g. if I enable video stabilizer the TBC gets disabled automatically, only one of the two can be enabled at the same time.

[amaipaipai]

I rather prefer the japanese NTSC 0 IRE setting and do the rest latter in post, on my Japanese gear +7.5 IRE show crushed blacks and whites.

[280634157]

Is there a 1080 DV that supports IRE=0 and has an S-video input? I would like to recommend one that is best for Panasonic or SONY 4:2:2.