Understand Video Scopes

EhabMElkhooley wrote on 4/13/2004, 1:01 PM

Hi Everyone,
I usually make all my videos inside Vegas & render to DV (using CANOPUS codec with progressive scan), then I import it into Edius (CANOPUS'S editing application) & record it through S-Video out on any analog media like VHS, S-VHS, SP-BETACAM ...... etc & When previewing on an external monitor everything goes OK.

Things used to go well until I made the first video for broadcast on a satellite channel & it was a disaster, the gain was very weak, colors almost washed-out.

I used SP-BETACAM for the output (they don't have DV hardware at this channel VERY WEIRD!!!!!!) Does this type of media affect the video signal?

A lot of people told me that using video scopes in Vegas 4.0 will help me to be sure of everything before releasing my video as previewing on external monitor may be misleading because of differences between monitors & I found a post on the forum talking about the same thing.

Can anyone tell me what am I doing wrong?
& is it that important to understand Video Scopes?

Sorry for not being short I wanted to explain all the details....

Thanks in advance, you've always been helpful for me.

Comments

David_Kuznicki wrote on 4/13/2004, 1:26 PM

(wow, two plugs for this book in one day! I deserve money from the publishers, don't I?)

Since scopes are a bit of a broad topic, I'd say pick up a copy of Color Correction for Digital Video. Not only does the book walk you through color correction, it explains how to scope your video & what they all mean.

As a side note, how the HELL did you manage to get something up linked and (assumably) broadcast without knowing anything about video scopes? That's TV 101! Is this what television is coming to?

Enough ranting... I'm still in college & I'm already feeling like an old-timer because I know how to do some of the basics, instead of just running around with a camcorder!

TheHappyFriar wrote on 4/13/2004, 2:46 PM

I worked at a TV station and we had 1 scope. but, it was broken so we didn't use it. It was very annoying. :(

The guys who are sending it via satellite should also have a scope of what's going over the air and should be able to adjust the output signel to compensate for what ehab didn't get perfect. Sounds like it's an even bigger problem when a company broadcasting via satellite doesn't spend the $5.15 an hour to have someone monitor what's going over the air! :)

rs170a wrote on 4/13/2004, 7:22 PM

Ehab, here are a number of sites by leading manufacturers of waveform & vector monitors for you to read through.

An excellent series of video test & measurement application notes (#14 is
the one you're interested in) is at:
http://www.videotek.com/notes.html

Articles from Tektronix, one of the main waveform/vector
monitor companies, are at:
http://www.tektronix.com/Measurement/App_Notes/PicQuality/index.html
http://www.tektronix.com/Measurement/App_Notes/NTSC_Video_Msmt/index.html
http://www.tektronix.com/Measurement/App_Notes/Component_Puzzle/index.html

Mike
(a firm believer in understanding what those squiggly green lines really mean)

Spot|DSE wrote on 4/13/2004, 7:25 PM

Sorry if I'm being redundant, but here is an excellent book on the subject.
http://www.cmpbooks.com/product/1220

If you can get your hands on a copy, Tektronik did a great vid a few years back. I see it every now and again on Ebay.

EhabMElkhooley wrote on 4/13/2004, 8:50 PM

Thank you everyone, You've been helpful and friendly as usual.
Don't know what to do without your help.

Of course any video editor must know some about scopes but, I wanted to know a decent source to get the info from because the more I read articles by editors the more I get confused.

Thanks again

farss wrote on 4/13/2004, 9:16 PM

Well, a few questions spring to mind.
Why are you rendering as progressive?
And why such a convoluted path to get to SP?
You could go straight from Vegas to SP using an ADVC-100 or better still ADVC-500 to give you RGB into SP machine. Just be a tad careful some SP machines need you to genlock the source, run a short BNC cable from a "T" piece to the Ext Sync in fixes the problem.

If you really must go down such a tortuous path then I'd suggest the scopes in Vegas are only part of the answer. You need to play back the SP tapes into A) a decent studio monitor and b) into a hardware vectorscope and / or waveform monitor. Check how the bars that started out in Vegas look. On the vectorscope you should have a set of markers and the bars should line up with them.

It could be that the station has got it wrong but until you know for a fact what you put on the tape I'd not broach that with them for fear of serious egg on face.

And BTW DV25 is not a broadcast standard which is why you don't see a lot of it in TV stations. Some may shoot on it so they'll be able to ingest but I doubt you'll ever see DV in the transmission side of a station.

EhabMElkhooley wrote on 4/14/2004, 1:45 PM

Thanks for you reply farss.
First I must go down such a tortuous path because I own a DV-Storm2 Pro card & I want to benefit from the component-out feature.
Second I render progressive because of some problems while importing some lower field first PAL videos into Edius.