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Vegas 8 IRE issues…Please help
Excuse me if this has already been addressed but I cannot find an answer. We’re currently running Vegas 8.0c with an AJA Xena LHE card. The problem seems to be with the IRE levels once it gets to broadcast. Our spots look horrible once they get to air. I called master control at the station any they say our tapes are showing 0 IRE or below. Im confused by this because the spots in question show a clear 7.5 IRE baseline through Sony’s internal scope. When we export to our Betacam we are using the Sony YUV codec and previewing it through the AJA card to a calibrated broadcast monitor through component RGB and it shows very accurate correct color. Unfortunately we don’t have an external waveform monitor but I don’t think that would tell us anything because we also rendered the same file to DVD using MainConcept MPEG 2 and it looks on air also. What I mean by horrible is that it looks like the luma is turning to mud. Everything that is black or any value of black is getting crushed down and filled in. It looks like mud when it hits the air. Again, internally on all of our monitors through component it looks great. Please help!
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4 Replies
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The bottom line is that you really do need to get an external waveform monitor (and vectorscope) as the scopes in Vegas cannot be trusted.
Glenn Chan has talked about this exact issue before on various Vegas forums and I’ve learned to trust his opinions.
For example, here’s one quote of his:
The Vegas waveform monitor can be confusing behave it doesn’t behave like a real vectorscope and it’s ambiguous. You notice how the waveform changes when you go into the settings and change things around? IMO it’s dangerous because you only know if you have correct levels if the settings are correct. And it’s difficult to tell if the settings are correct unless you go into the settings window (on real waveform monitors this is not an issue because they have indicators of what mode you are in). -
Thanks Mike. I’ve always been an Avid jockey and just recently moved into the world of Vegas. I’ve always trusted the internal Avid waveforms so I never knew there was any reason to doubt Sony’s. Frustrating, but thanks for the information. I just can’t understand how it can be so far off. Big question, why would my preview monitor (which is calibrated correctly) play back my Beta SP dubs and look perfect? I would think that with a calibrated monitor, what you see is what you get. Am I wrong in this? Does the IRE level only come into play when it is broadcast?
Thanks again for your input.
Joe -
“I would think that with a calibrated monitor, what you see is what you get. Am I wrong in this?”
Sort of. I set my program monitors up to SMPTE bars but have always thought of this as something that is used for colour (blue gun off) and luminance correction purposes (PLUGE signal) and not for verifying the levels of the signal.
Does the IRE level only come into play when it is broadcast?
Yes. For home use, it really doesn’t make that much difference as most folks never bother to properly adjust their TV set anyway 🙁
A good broadcast engineer is very picky about ensuring that the video signal you give them is between 7.5 & 100 IRE and that the chroma levels fall within allowable limits.Check Glen Chan’s article titled The 7.5 IRE Setup Problem for more info on this rather confusing issue.
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Thanks again Mike. I really appreciate your input.
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