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View Full Version : ALERT: vertical chroma offset



Lord Beowulf
02-04-2004, 04:13 PM
Hello,

we tried everything, but we couldn't eleminate this chroma offset (see picture), where you can see the red border at sharp contrasts.

We checked the output from the BVW-70 and it's ok. The signal goes through the SX-8. Same prob with component and composite.

Did anyone know what to do? Or did anyone discoverd this with his own toaster?

Beo

SCS
02-04-2004, 04:49 PM
Does the same problem exist if you remove the SX-8 and use the original multi cables?

I do not own an SX-8, however other capture cards (DPS, Matrox) have a software control called "Y/C" offset which allows you to shift the Chroma portion of the signal horizontally or vertically in reference to the Luminance - any chance the SX-8 can do this?

Lord Beowulf
02-04-2004, 04:56 PM
We just checked it without SX-8, but same problem.

Then we tested every single option of the advanced procamp tab, but nothing.

same with the preferences...

Then we made a testpicture in photoshop and this showed up exact at our video monitor. Therefore it has to be some issue with the input...

Beo

MediaSig
02-04-2004, 06:07 PM
...does this happen with all the footage you have tested or just the current footage you are using?

I ask because I once used a Sony 400A Betacam that unfortunately had the color CCD chips out of alignment. The result you have above it very similar to what I was seeing the footage (of course this was after we finished the shoot :-( )


Just a thought.

Greg

Lord Beowulf
02-05-2004, 02:59 AM
We checked the footage and the BVW-70 by linking it directly to the video monitor - the picture is perfect.

We have found a picture where you can see the error a lot better. It's a person with a black sweater. And at the border from the sweater to the neck you can see a cyan offset and at the sweater you can see a red offset... By tweaking the advanced procamp settings we could reduce the error slightly but couldn't eleminate it :(

Beo

bradl
02-05-2004, 08:03 AM
These kinds of errors can be introduced when using component (YUV, R-Y, B-Y, Y or RGB) if your cables are not the same length or do not take the same path (patch panel or something). Maybe check that...?

Lord Beowulf
02-05-2004, 11:44 PM
Thanks bradl,

but checked that before, we have three single cables for YUV and they have the same length. Double checked it by switching to another cable - same error.

Put in a new picture where you can see the offset. We have two toasterboards here and both have the same prob :(

Could anyone with a BetaSP BVW-70 connected through YUV confirm this?

There are no offsets when going through firewire.

Beo

SCS
02-06-2004, 08:58 AM
When you checked the BVW70 on a monitor, did you use Component or Composite?

btw: judging by the vertical black bars in your pics, did this footage originate on DV which you then transferred to Beta and then captured from the Beta?

Lord Beowulf
02-07-2004, 04:05 AM
We checked the signal with composite and component on the video monitor.

The footage is recorded with a betacam and then the cassete is put in the BVW-70.

Yesterday we used a testpattern generator and we could eleminate the vertical and horizontal chroma offset with advanced proc amp settings.

Then we recorded the testpattern with the BVW-70 and played it back via Toaster and everything is fine, but when we put in our footage same problem occured, therefore i think it's probably the recorder of the betacam. The only issue is, that when we play back the same footage on another BVW-70 with our discreet everything is fine...

Beo

bradl
02-08-2004, 09:09 PM
If I am following this right, you may have narrowed it down to a BVW record problem? If so, I would recommend sending the BVW to Sony for a complete setup.

If someone with a happy tweaker has messed with some of the boards you may never get it right again. We have sent several machines to Sony for re-calibration in the last few years and they do a good job, for a resonable price and get your machine back in a few days.