accuracy of Vegas' waveform monitor and legality of generated media

[Josh Bass]

All I have to say is. . .sigh.

[Edward Troxel]

I agree with you Josh. Personally, I don't even worry about it UNLESS the video is going to be broadcast. For standard event work being distributed on DVDs, I've never had any complaints.

[Josh Bass]

Let's take another tack.

I'm just trying to figure out what's objectively "right" here. Regardless of whether I'm aiming for NTSC or not, the checking of the "7.5 setup" both should be either the right way to do it or the wrong way, as far as accurate readings, no? What I mean is, objectively, the blacks that Vegas generates (this could be the black you get from a blank area of the timeline, or generated media) either ARE or AREN'T 0%. If you have the "7.5 setup" box checked, the blacks read as 0%, but if you don't have the box checked, it reads as -7.5%. If I were to look at those blacks on a real external waveform monitor, what would I find? 0 or -7.5?

Also, I thought if one was using DV, DV blacks are 0%, so you wouldn't check that "7.5 setup" box while trying to color correct/grade. Isn't that correct? Footage orginated on an XL1s on default settings.

Oh, and another thing: the differences between NTSC legal and the full limits of what one COULD do if there were no legal limits aren't THAT big of a deal, are they? What I mean is, if, just to be safe, I always just made everything legal, I wouldn't be likely to screw myself in any significant way, would I? I mean, I know if I went to film (yeah right) then 7.5% would look a little grey, but, other than that?

[Glenn Chan]

Josh, your 0% percent doesn't have a unit on the end so it's kind of vague that way. I presume you are talking about 'Vegas WFM units' (WFM=waveform monitor; I made these terms up). The problem with Vegas' WFM is that checking the boxes in the settings will change the values. So to accurately communicate here, you'd need 4 terms for each possibility on the WFM monitor.
I'll just call them "Vegas WFM 7.5IRE studio RGB", "Vegas WFM 0IRE no studio", etc.
But the thing is, you may not really need to concern yourself with them.

2- If you're working with the Sony DV codec throughout your chain (and never the MS DV codec), then checking the studio RGB box is the right thing to do (check the manual).

3- In your scenario (making a DVD), you probably want your master to conform to the standards for a digital master. For an 8-bit format like DV, blacks should be at 16 and whites at 235. I believe the correct unit would be Y prime, since DV decodes to Yprime Cr Cb format. In Vegas you can't see these values since Vegas works in RGB color space. But if you look at the histogram, 16 (Vegas histogram) should correspond to 16 (Y prime) and 235 (Vegas histogram) to 235 (Y prime).

*I'm just assuming that 16 (Y prime) corresponds to 16 on the Vegas histogram. You can't see those digital values in Vegas (as far as I know) and there's a possibility that Vegas is wrong. If someone has an *external* vectorscope then they can check all this stuff out.

The deal with the Vegas WFM:
The Vegas WFM is supposed to show the same readings as hooking up an external WFM to your DV device. However... some DV devices put blacks at 0IRE and some at 7.5IRE. Vegas doesn't know which one that is.

So first off, figure out what kind of equipment you want to monitor for.
Equipment that puts blacks at 7.5IRE: Most/?all? DVD players, professional video equipment set to 7.5IRE (such as the deck the broadcaster will play your master on).
Equipment that puts blacks at 0IRE: Consumer/prosumer equipment, Japanese equipment.

For DVD, you want to monitor for equipment that puts blacks at 7.5IRE.

I don't think you'd ever really want to monitor for equipment that puts blacks at 0IRE, unless it's for Japan or PAL.

4- If your equipment put blacks at 0IRE:

Suppose you're connecting a TV to your system. Feed bars from Vegas to it. Calibrate the monitor to those color bars... set contrast and the PLUGE bars.
see http://www.videouniversity.com/tvbars2.htm

In Vegas, 16 (Vegas histogram) should be output at 0IRE. You're calibrating your monitor to blacks at 0IRE. So, you now have your monitor showing things properly- it won't clip/crush the blacks.
*It may be that in practice your monitor won't 'like' blacks at 0IRE. I'm just assuming things work like they should.

Ok, so if you do that: you should have proper digital levels, and they'll appear right on your monitor.

5- Here's where I'll probably just confuse you.

Suppose you now want to make an analog betaSP master through your Sony DSR11. The DSR11 is a ~$1500 "prosumer" deck that puts blacks (blacks that are 16 in digital units) at 0IRE, and can't do 7.5IRE (from what I've read).

If you want your life to be easy, get a deck that puts blacks at 7.5IRE. Or get the Canopus ADVC box, which I believe can be set to put blacks at 7.5IRE.

If you want to be cheap, here's how you can do things in Vegas:
Set Vegas to monitor for equipment that puts blacks at 0IRE. In the Video scopes setting, uncheck "7.5IRE".
Now you want to add artificial setup so that the blacks in your footage end up at 7.5IRE. So for example, you could add the color corrector filter and put 16 in the offset. This should bump blacks from 16 to 32 (16+16=32). So when you print to tape, 16 (digital, Y prime which should be the same as vegas histogram units) will be at 0IRE. 32 (digital) will be at 7.5IRE. In vegas, you already put your blacks at 32 digital. So now they'll end up at 7.5IRE on your betaSP tape (when going through the DSR11).

The whites will end up at 235+16, so you have to use the gain to make things right.

Ok, now suppose you print your master onto DVCAM also (or DVCPRO) and you send that to a broadcaster for broadcast. Their deck is probably set to put blacks at 7.5IRE. So now, your tape's blacks (which are at 32 digital) will end up at 15IRE (too bright). Whoops.
So don't do that.

6-

DV blacks are 0%

DV blacks are supposed to be at 16, and whites at 235. As mentioned earlier, I believe the correct units would be Y prime. DV stores the video compressed + error correction, and that video decodes to Y prime Cr Cb. This is sometimes confusing written without the prime symbol on "Y" (YCrCb), or referred to as YUV.
Vegas never shows you things in Yprime Cr Cb... so you're kind of guessing about what it converts those values to.

A good resource on this stuff is http://www.poynton.com/ I haven't looked through all the materials on that website. It doesn't directly pertain to Vegas, but has lots of video engineering information.

Oh, and another thing: the differences between NTSC legal and the full limits of what one COULD do if there were no legal limits aren't THAT big of a deal, are they? What I mean is, if, just to be safe, I always just made everything legal, I wouldn't be likely to screw myself in any significant way, would I? I mean, I know if I went to film (yeah right) then 7.5% would look a little grey, but, other than that?

I think you could potentially make your footage look worse than not applying the filter.

In Vegas, the broadcast colors filter can excessively limit your color space (If you use the conservative setting). Bright + saturated colors will be brought down in saturation, which can look bad on some rare images.
Should I post up a picture for you?

[Josh Bass]

Sure.

I haven't used the filter yet. I was going through the elements in the project and manually taking them to legal limits (e.g., on the solid color white, use a brightness/contrast filter, and lower the brightness 'til the whites read at 100% instead of 110%.

I'll have to chew over the rest of that when I've had a nap.

The consensus seems to be leave that 7.5 box checked, if I'm hearing (seeing) you guys right.

Oh, and. . .if I were to check the 7.5 setup box, then I want to have blacks reading 7.5? or 0?

[Mike Kujbida]

Josh, see if JVC's 5 min. flash black setup tutorial at http://pro.jvc.com/pro/attributes/pr...p/JVC_DEMO.swf helps to clear things up.

Mike

[Josh Bass]

I think I've watched that before, but I'll watch it again. Thanks.

[Josh Bass]

Yeah, that's what I thought. Watched it and still unsure of how to handle the issue at hand.

Seems like according to that, until I deal with analogue source, the idea would b to monitor with that 7.5 setup box UNCHECKED. But I'm probably wrong for some reason.

[Glenn Chan]

Josh, here's what I think Vegas does.

The waveform monitor in Vegas is supposed to match what you'd see on an external waveform monitor hooked up to the analog outputs on your DV deck/camera.

Your deck/camera either puts 16 (digital luma values) at 0IRE or 7.5IRE. An external vectorscope would show which is the case. Vegas doesn't know whether your deck puts 16 (digital luma values) at 0 or 7.5IRE. So, you have to tell Vegas what your deck is doing. That's what the 7.5IRE setting in the Video Scopes setting is for.


Anyways, you don't need the waveform monitor in Vegas per se. Just use the histogram, which shows you the digital luma values for your digital video. Keep important details between 16 and 235 on the histogram. It also has more detail that the waveform monitor.

So, if your target format is DVD players:
You know what DVD players put 16 (digital luma values) at 7.5IRE. So, you want blacks to read 16 on Vegas' histogram.
Your deck/camcorder may not put blacks at 7.5IRE. But, that doesn't matter because you are going to DVD.

[Bill Porter]

Glenn and all,

I just read and tried to comprehend as much of that information as I could, being as I'm a rookie at this stuff. I just graduated from a baby Panasonic to a DVX100A.

My goal is now to shoot and edit a documentary for broadcast. Of all the questions I have on broadcast-legal colors, the big one is, what would be the way you recommend for me to A) set up my DVX and B) set up my colors?

Anything anyone can offer me is *greatly* appreciated. I know how to get stuff done in terms of people and production skills but I feel lost about how to get started because I don't want to just start shooting willy-nilly with no forethought, thereby possibly creating a big problem for myself down the line. I want to shoot knowing at least my camera and my Vegas are set up correctly.

If this question is in the wrong area and warrants a whole new thread, I'll ask a moderator to move it.

Thanks

[Mike Kujbida]

Originally Posted by Bill Porter

My goal is now to shoot and edit a documentary for broadcast. Of all the questions I have on broadcast-legal colors, the big one is, what would be the way you recommend for me to A) set up my DVX and B) set up my colors?

As I don't own a DVX, I can't help you out there. I know that this site has a DVX forum so I'd ask for help there.

As far as setting up colors, my first recomendation would be to buy a decent field monitor and, more importantly, learn how to calibrate it.

B&H has the model I have, the JVC TM-910SU, for $610.00
It's a 9" model that's 4:3/16:9 switchable and can be AC or DC powered.
It also has underscan, blue gun only and color off, all very desirable features in a field monitor.

You may also want to invest in a carry case of some kind. Porta-Brace and Kata are 2 good manufacturers.

There's a tutorial called "Color Bars and How To Use 'em" at http://videouniversity.com/tvbars2.htm that I recommend memorizing :-)

Holler if/when you have more questions.

Mike

[Glenn Chan]

DVX100: In the menus, there's an option for 7.5% setup or something like that. DON'T turn it on.
See Adam Wilt's DV FAQ - scroll to the very, very bottom
You can fix things in post if you get it wrong, but its easiest if you leave that off.

My goal is now to shoot and edit a documentary for broadcast. Of all the questions I have on broadcast-legal colors, the big one is, what would be the way you recommend for me to A) set up my DVX and B) set up my colors?

It may be easiest to get someone else to pay for an online edit, and they'll handle the legalization stuff for you and format your master right. And they'll have a betaSP or digibeta deck too, setup correctly (stations generally only accept masters on betaSP or digibeta).

You could probably use Vegas to do the online edit (and if you want to do serious color grading, it can be the best platform because your edit is conformed already and the CC tools in Vegas are pretty good). However, a lot of things in Vegas aren't obvious. For example, fade to blacks will go under 16 (digital luma values) unless you add a solid color generator 16 16 16 RGB underneath.

You also have to figure out how to do an insert edit yourself. Or you can do the color yourself, and then bring your project to an online edit session and let them make the master.

[Bill Porter]

Thanks for the answers, guys.

First off I need to do some serious studying because I have no idea what most of those terms truly mean. But here are my further questions which I think will elicit the simplest answers:

1 - By "pay for an online edit," Glenn, are you referring to someone else doing all the editing, as in, I supply the tape and say "Make it compelling, please!" (LOL), and they do all the cuts, transitions, use of B-roll, choices of what and when and where, to their tastes? Or did you mean me doing the editing in Vegas and someone else tweaking what I've done to be broadcast-friendly?

2 - What does "conforming" really mean? I've searched the Vegas instruction pdf as well as online A/V glossaries and I never see an actual definition.

2 [continued :) ] - RE: the advice "if you want to do serious color grading, [Vegas] can be the best platform because your edit is conformed already". In this context does it mean "because your editing would already have been done in Vegas so you can just do the CC in Vegas too"?

3 - Pardon me for being the noob that I am, but, why is deck selection even an issue in terms of "formatting my master right"? Are we talking about *outputting* the edit to betaSP/digitbeta for submission to a station, or are we talking about capturing? If we're talking about capturing, it is puzzling to me that digital data on the DV tape on which I shot my clips, doesn't come out quite the same way depending on what device I capture from, be it my camera, or a cheapie deck, or a pro deck. It's digital data - hard numbers - so to my mind it should all get captured identically, unless you're tweaking the captured data at the same time. Just like how if you pop a DVD into a DVD-R or a pro DVD-RW or a home DVD player or a PSP, the data on the DVD gets interpreted the exact same way in each case.

Thanks so much for the help. Clearly I am on the exponential-growth part of my learning curve but I'm absorbing quickly, thanks to the help of everyone so helpful on this forum.

Edit: Forgot to ask - what the heck is an insert edit and why would I need to do it? I know what it means in terms of editing (meaning, inserting clips into the timeline as if you were cutting film and splicing it in someplace else) but the way you refer to it makes it sounds as if there's another meaning. I Googled it and found references to beta decks and DVC Pro decks that sound like there is a second, very different meaning.

Thanks yet again!

[Glenn Chan]

Sorry, I don't think my message was that clear.

1- Online edit: By that I mean pay someone else to do the finishing for your project. Making the levels broadcast-safe, putting your documentary on the master formatted properly.
In your words

doing the editing in Vegas and someone else tweaking what I've done to be broadcast-friendly

2- Conforming: By that I mean importing your project into whatever system you want to online or color correct/grade in. If you color correct yourself, this is easy because you don't have to do anything.

In this context does it mean "because your editing would already have been done in Vegas so you can just do the CC in Vegas too"?

Yes.

If you want to go to another system, you have to do an EDL or XML (not everything will carry over, and there may be bugs) or export a series of files (dissolves may not look right if you're doing drastically difference grades on both sides of a dissolve/fade).

Pardon me for being the noob that I am, but, why is deck selection even an issue in terms of "formatting my master right"? Are we talking about *outputting* the edit to betaSP/digitbeta for submission to a station, or are we talking about capturing? If we're talking about capturing, it is puzzling to me that digital data on the DV tape on which I shot my clips, doesn't come out quite the same way depending on what device I capture from, be it my camera, or a cheapie deck, or a pro deck. It's digital data - hard numbers - so to my mind it should all get captured identically, unless you're tweaking the captured data at the same time. Just like how if you pop a DVD into a DVD-R or a pro DVD-RW or a home DVD player or a PSP, the data on the DVD gets interpreted the exact same way in each case.

Sorry, I'm talking about about making a master tape for your project.

Broadcasters typically accept only betaSP or digibeta for masters (not miniDV). Chances are you don't have one, and your system is not setup for one.

As well, they have requirements as to the formatting of that master.

[Bill Porter]

Thanks and no need to apologize, Glenn! Any info is much appreciated, and besides, it is my own ignorance that is the problem, not your explanations, hehe.

Gotcha on the beta master, thank you. I did just read something about how capturing with different decks gives different results; I've searched and searched and can't find the thread, though. Maybe it was referring to decks that add setup.

Glenn, do you work in video (and in Vegas as well?) for your day job? You clearly have so much knowledge and experience with this stuff I'm figuring you are either a pro or an amateur with a 5th degree video black belt, LOL.

Thanks again Mike and Glenn, I certainly will holler again soon when I'm trying to get my brain wrapped around the next thing.