NTSC monitor setup Zero or 7.5?

[Bill Peterson]

Plugging up the DVX to a Sony PVM 1354Q (old) pro monitor. In the monitor setup menu under the NTSC Setup levels menu you must choose Zero or 7.5. Which Do I Choose?

It of course changes the blacks, the way you set up for the bars and how you tweak the camera. So is the DVX outputting, through the S-video out, 0 IRE or is it outputting 7.5 so as to play nice with the average TV set? And where does all that leave us when we get a switchable choice as in this monitor?

Thanks
Bill

[Scott Chapin]

You should set your monitor to 7.5.

[Preston Herrick]

If you are shooting with the camera set to 0 IRE (which you really should be) then set the monitor to 0 as well, then calibrate as you normally would. Feeding a monitor a reference signal of 0 when it is expecting 7.5 will not allow proper calibration - becomes a guess. Has to do with the plunge bars in the lower right corner of SMPTE bars.

[Scott Chapin]

I think the jury might be out on that one? Most NTSC cameras for USA distributiion have an analog output setup of 7.5, expecting to be plugged into a VCR or TV. I have not heard that the DVX100 is an exception.

I assumed the question implied the use of the analog outputs. In any event, play the color bars to the monitor and check the pluge on the monitor.

Of course the DV signal is 0, but then the firewire is not being plugged into the monitor?

When you set setup in the camera, it is in reference to the DV recording, and not the analog outputs, and yes, you don't want to ad setup to the recording. That would create a setup of 15 at the analog outputs.

[Preston Herrick]

My tests show that the DVX outputs, via analog, whatever you have the camera set to record in, be it 0 or 7.5 IRE. Higher end cameras are often switchable (I have one) in that you can record at 0 IRE but set the analog outs to 7.5. I would not assume, however, that all DV cameras and decks are outputting 7.5 - in fact, many don't or can't.

[Scott Chapin]

<<<-- I would not assume, however, that all DV cameras and decks are outputting 7.5 - in fact, many don't or can't. -->>>

Maybe someone else will step in, I would like to know! This statement means most consumer DV cameras incorrectly output a 0 IRE, which I doubt, as all consumer monitors and VCRs are 7.5IRE.

I record at 0IRE in my DVX100 and it plays analog out beautifully on TVs. If what you say is true, this would not be the case. My Sony PVM-8045Q does not have a setup option, but plays my DVX100 back beautifully.

The 0 setup option on monitors is to accomodate Japanese NTSC, which in fact does have a setup of 0, like PAL.

[Preston Herrick]

<<<-- This statement means most consumer DV cameras incorrectly output a 0 IRE, which I doubt, as all consumer monitors and VCRs are 7.5IRE. -->>>

That's right - they output 0 and domestic consumer monitors and VCR's, 7.5. I didn't say it all made sense - that's just the way it is :)

If you still want a second opinion check here for example:
http://adamwilt.com/DV.html

[Scott Chapin]

Adam Wilt:http://www.adamwilt.com/DV-FAQ-tech.html#Setup


Now, when you play back to analog, what happens? Digital levels get converted to analog levels, and that's where setup enters the picture (or not).

In Europe and Asia, analog video's blacks are at zero voltage: 0mV PAL, 0 IRE NTSC. In North America we add a slight offset, the infamous 7.5 IRE of setup, for historical reasons (the DC regulation of early sets was poor, and electron beam retrace suppression didn't exist, thus the designers provided a safety margin between "black" and "blanking" levels so that retrace wouldn't be visible even if the viewer's TV set was slightly misadjusted).

[Preston Herrick]

I think you're mis-interpretting what Adam wrote or I don't understand you. He goes on to write:
______
"Huh? Remember, I said "at NBC." NBC and their partners in crime will be using proper, broadcast/professional NTSC DVCPRO and DVCAM decks. Such decks have, buried in their menus, the option to "add setup". In Japan and Korea, that setting is properly turned off. In the USA, that setting should be on. By the same token the better camcorders offer "add setup" switches in their menus for their analog outputs.

A similar setting removes setup on incoming analog signals; it should be on in the new world, off in the exotic east.

Now, the Rest of Us may be using lower end gear: DSR-20s, DSR-11s, PD150s, even (shudder) consumer gear. None of these low-end decks and camcorders have "add setup."

So if you take a tape shot in a DV or DVCAM camcorder and play it back in one of these low-end decks, the analog output will NOT have setup. The playback will be fine in Asia, but it'll be "too dark" in the Americas."
______

But I don't want to argue with you. I'm sure somebody else will chime and confirm what I've been saying.

Try this. Feed SMPTE bars (not from the DVX) to one input of your monitor. Make sure it is properly calibrated to these. With your DVX set to 0 IRE and the bars on, send an analog out to another input on the monitor. Switch between the inputs. Notice how the DVX blacks look crushed? Notice how all the plunge bars look identical? Now, switch your monitor inputs to 0 IRE in the menu. Now the DVX bars are correct (and if you switch back to the other input those blacks will now be raised too high).

You can also check out this recent thread on another forum:
http://www.uemforums.com/2pop/ubbthr...=5&o=7&fpart=1

[Stephen van Vuuren]

Preston:

Thanks for the link - in that discussion I found a link to good tutorial on setup issues even though it's JVC (sorry Panny):

http://pro.jvc.com/prof/Attributes/i...&feature_id=19

[Ken Tanaka]

That's an excellent tutorial, Stephen. Thanks for passing it along.

[Scott Chapin]

Preston,

Yeah I see now, the wording in two different sections mislead me. So...why doen't the setup look incorrect on my Sony PVM-8045Q, and why wouldn't it have a setup option? The pluge looks perfect on it.

I know the monitor auto selects PAL, NTSC etc, but how does it know the signal is 0IRE?


Thanks,

Scott

[Preston Herrick]

Scott, I have an 8042Q I use in the field and it doesn't have any kind of menu system either for setting input IRE level. A miscalibrated monitor doesn't necessarily mean your picture will look bad. In fact, it may look great - but.... it won't be "right". Just means you're not seeing the most accurate representation of what's going to tape. (You really need a bigger monitor than this in the studio, too)

Then that raises the question: Why can't I just calibrate my monitor that's expecting a 7.5 signal to the 0 IRE bars? Well, you could but it would still not be quite "right". You have two solutions. Either insert a proc amp between the camera output and monitor - which could be a hassle; or adjust the monitor to 7.5 level bars (which you could do by temporarily switching the camera to 7.5 and feeding it's bars) and then adjusting the brightness control until just before the far left plunge bar increases in brightness. This link will better explain what I'm talking about.

http://greatdv.com/video/smptebars2.htm

But in the end, your shooting needs may or may not require you to go to such lengths (I shoot all the time without a monitor with great results). In that case, adjust the best you can, don't worry so much about it, and get on with the business of shooting.

[Bill Ravens]

do do this correctly, as I understand it, you need to adjust the brightness on the monitor until the left two pluge bars on the NTSC colorbar chart disappear into one another.

[Preston Herrick]

Bill is correct but that is only if you are feeding the monitor 7.5 IRE video. With a 0 IRE signal you have to continue raising the brightness (or switch the input level on the monitor, if that's an option).