View Full Version : SX-8 calibration

03-11-2003, 05:04 PM
Well, I thought this was addressed somewhere, but I can't find it.

What's the dealio with the SX-8 calibration controls in the preferences menu? Can one adjust the component output levels for the SX-8. Cus if you can, I can't for some reason and I can't find any mention of these controls in the manual. What up?

P.S.: The reason I'm hoping It can is because my component out signal sure seems brighter than my composite out signal and I'm thinking this is the reason. If not, I'm at a loss.

03-12-2003, 09:50 AM
If you are running Betacam component, you MUST set the Preferences Output Pedistal to OFF (0IRE)

Everyone else's (MII, D1,2,3,5,9, DVCPro, DVCam, DV, VHS, 2"Quad, 1" C, Everything get it) uses 7.5 IRE.

The 7.5 IRE increase means a Betacam with no setup (the Pedistal, or where "black" is) will have its pure white at 107.5IRE rather than 100IRE.

This has been a headache in multi-format environments for years.

We used MII, and Betacam in a component analog 5machine edit suite. and because we were a MII house mainly, we had to jack the Beta signal around to make it "work"...

Why 7.5 IRE you ask... The folks who invented NTSC (Never Twice the Same Color) determined that because the transmitters have no way to broadcast essentially 0 (zero) signal (black) they put in "setup" of 7.5 IRE which appears mostly black (without 0 IRE as a reference) and is enough of a signal to be transmitted, it also alleviated some TV set issues that are irrellevant considering all TVs today are solid state.

Why did Sony decide to have the native Betacam signal be un-transmittable? Well ya got me there...

Maybe to sell interface equipment, to cover their marketing costs....

My other idea (I'm hurrying, really) is that perhaps the Component signal is correct already, and maybe your Composite signal is double terminated...

Just my .02 without having seen the problem directly...

03-12-2003, 11:35 AM

The IRE 7.5 pedistal has been and continues to be a source of confusion to me. I haven't been making any material for broadcast. I have read numerous times that all the DV formats record at 0 IRE (which is the Japenese "NTSC" standard). I'm unsure about playback options. So are you saying that if I want to broadcast a DV tape clip on USA NTSC, I first need to convert or otherwise add in the 7.5 pedistal?



03-12-2003, 12:13 PM
Thanks Jerry, but I am aware of the pedestal issue. What I am hoping to be able to do is adjust the component output signals in the preferences section so I can have relatively comparable levels on both the component and composite outs at the same time. Adjusting the pedestal setting would bury the black on the composite outs and we don't want to do that.

So the question remains: Why are there calibration controls for composite, y/c, and component in the SX-8 calibrations section of the preferences when they appear to do nothing. Can I get them to work or is Newtek needlessly teasing us?

03-12-2003, 01:05 PM
Ow! :(

I guess I'll have to set MY output to 0 then. Seeing as how we are Sony Beta component here.

And, Jreble: I have tried to "discover" how to set the output levels from the SX8 to our decks, and have been told the BOB out is uh, fixed. Well, that may be so, but I still have a third-party waveform/vectorscope on it.

I *still* can't tell you how we missed the 7.5 IRE discrep, tho...


03-13-2003, 07:51 AM
We play our DV through DVCPro decks only, and they have the setup.....

I'll have to look into your question of DV having setup in its core format.

Weeel, after this post I fiddled around with the "settings" for the SX-8... sure enough: "fixed", .... maybe T3 has this "quirk" repaired.

BTW as a general rule we are talking component Y, R-Y, B-Y signals here...

I believe (but could be wrong, I'll scope it at lunch) that Beta composite outputs HAVE setup....

johnq, you are correct, Japanese NTSC has no setup... thats why Sony did this.

As for broadcasting your DV programs: If the signal isn't compliant, trust me the station will "fix" it before it airs.

How they achieve this is probably something you don't want to hear....

Plus if you are giving them the source material on DV proper, they will probably play it out on a DVCPro deck anyway, thereby adding the setup...


03-14-2003, 10:53 AM
Just a follow up. While checkin out another issue with my BOB, I noticed that the SX-8 calibration controls actually do make adjustments to the inputs. Theres one set of controls for all the Y/C inputs, one set for all the component inputs, and two sets for composite inputs. Strange that these are used for input adjustment when each input also has individual proc amp control. It's also odd that nobody around these boards knew that about those controls either. Hmmm...

03-14-2003, 11:07 AM
The SX-8 calibration is to correct for signal differences between video coming in through the main toaster board, and video coming in through the daughter card. The signal differences typically only show up in the U/V offsets of component video signals.

T[3] has an "autocal loopthrough" feature on the procamp which will determine and set these signal differences. So they will be much less necessary to understand..