Bi-dir A/D converters again again

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B.Verlik wrote on 4/6/2005, 11:04 PM
Thanks for putting up with me, Bob. I'm really surprised that there is not an easy switch to adjust this. When I checked the IRE with the 7.5 off, I had all 3 colors plus luminance at the same time. I didn't really know which one to go by, but if I remember right, all of them went down to zero. But if I engaged the switch to 7.5, it seemed like the graph switched positions, but otherwise nothing changed. So it went to zero with the switch off and still looked washed out. The other weird thing is, it usually looks normal as I'm capturing, but looks washed out when I play it back on the timeline. Noticeably different from the ol' datavideo DAC-100, which seemed to make the blacks, black. Now I've already noticed that a lot of my older VHS tapes look slightly lighter, in the black range, than the new Satellite signals do live, when I compare them 'side by side' on the TV. Moving the contrast between 0.15 and 0.20 (depending on the VHS signal and if I add 'black text' to cover TV logos) has been my usual fix.
Right now, I'm in the middle of a 60 hour render (using TMPGEnc to both 2-Pass render and a noise reduction filter), so I can't go re-check until sometime Friday.
Seems like some IRE settings in the 'capture' section of Vegas would be a bonus. Considering who's name is on the product now, you'd think they'd at least make it work with their own "Pass-through".
I appreciate your help. Thank you.
farss wrote on 4/7/2005, 12:27 AM
Again I;m no expert as this stuff being a PAL man.
From my understanding there's NO setup on DV, it's only applicable in the analogue world of NTSC. That's becuase it was introduced in the early days to cope witha problem in sync levels and early electronics. DV doesn't have sync pulses as such so it doesn't technically exist in that world.

But all that aside, most of the Sony DV camcorders record very hot video, well outside broadcast levels, makes em easier to sell, just looking at the video I just captured from a 570 it looks pretty tame (read washed out) compared to my D8 footage so this could also be your issue. You;re used to seeing the hot footage from a DV camcorder.

Now that you've got the idea of what the scopes are for you can try this.
Put some footage you thinks OK on one track and some that you think is washed out on another. By muting one track in the header you can quickly see the difference on the scopes. Obviousoy this only makes sense if the scenes are similar, a shot of a polar bear in a blizzard is going to look way different to a brown bear in a basement with the lights out, well OK you get the idea. That's why bars were so vital with analogue video, they were a standard and even if things had drifted off a bit through the chain using scopes they could be bought back to the right levels against a know reference.

Anyway to give you some clues, when you look at ths histgram if the channels have most of the energy (fat parts) at the top and bottom then you've probably got crushed blacks and whites, if it's too much at the bottom and none at the top the blacks are crushed and vice versa.. From the little you told me it sounds like your washed out video just needs a bit more gain to give it a bit of life, the blacks are just black which mean some of them are dark grey and the white end is just making it to white so some of your whites are looking a bit light grey. I'm thinking as I said just a LITTLE gain (contrast) using the FX I mentioned will fix your problem.
Bob.

B.Verlik wrote on 4/7/2005, 11:56 AM
Again, I thank you for taking the time to explain. I'll be able to live with it. It still looks better than the signal from the datavideo DAC-100, especially the VHS transfers. I'm surprised that nobody's seemed to agree or mention that when you use certain 'text', that it exaggerates the problem even more. This I noticed even when I used tha datavideo. Instead of 'blurring' out the logos or text crawl, I'd use huge 'Text' hyphens or periods to cover the logos because it seemed to render much faster and I didn't really care about the look of covering the scrolls that much. I would adjust the contrast for the video plus the station logo cover, then when the section came up with a news scroll and a station logo, I'd have to split this section apart and add even more contrast to get it back to normal.
As far a the Scopes go, I think I understood the idea of how they measure, it was the switch thing that threw me for a loop. I guess I was expecting someone to say that there was some hidden filter or plugin that dealt with this. I will need time to really put the scopes to use properly.
Ironic....I'm trying to do the simplest thing in video. A couple of more years and I may be able to copy a tape right.