Blue tint in white areas on capture

[parsonic]

Hi I'm using my ADVC300 to capture anologue vhs to my pc. My problem is the white areas seem to to get islands of light blue in them spoiling the overall look of the scene. It can be removed to some extent by changing the Hue slider but this kills the colour balance. Any Ideas

[GrassValley_BH]

What kind of lighting was the footage shot in?

[parsonic]

Thanks for the reply. I have shot footage indoors and outside. Using the cameras white balance settings for tungsten light, sun light etc. This blue cyan tinting can be seen in the white clouds outside and on the white fur of our dogs indoors.But I think the problem lies with how the ADVC300 handles the really white areas. I have set up another computer using a Radeon 128 rage all in one wonder for capture from the same VCR and the effect is much less pronounced. (although the Radeons quality is no match for the ADVC using the same capture settings). I reason that the cameras white settings are slightly off and somehow the ADVC300 exagerates the problem.

[GrassValley_BH]

First off I'd reset the ADVC300's input adjustment settings using Picture Controller or the hardware controls. It might simply be an overpunched contrast or something similar.

It also might have to do with the DV color sampling, which is 4:1:1 for NTSC and 4:2:0 for PAL. This will cause some amount of "bleeding."

Adam Wilt's site has some great pictures illustrating sampling along with his DV FAQ.

[parsonic]

Thanks for that Brandon. Alan Wilts site made interesting reading. I have seen this colour bleeding he shows but this is acceptable on my old vhs tapes. The problem I encounter is more like the white clippng he discribes although why this should change the white to a light blue? I am now setting both computers up to use the same software during capture.(but different capture cards).Then I will swop the captured files and view each on the others screen to see if its a viewing/screen problem. The default settings didn't help. I'll report back when i've finished.Regards Parsonic.

[GrassValley_BH]

Hey Parsonic,

It's quite possible that your display settings and/or video card overlay settings are also adding confusion to mix, so if you can generate a color bar output (the EDIUS demo will do this if you can't find or generate one on your own) then you'll have a reference for further calibration.

Unfortunately color calibration is an evil feedback loop with too many variables!

[parsonic]

Hi Brandon, managed to get every setting in the software, and the screens matched as near as possible, and presto those blue patches in white appeared on my old computer! Now my problem seems to look more likely it's the source, ie. the tapes or the VCR. I tried to grab an image to show you what I am seeing but the blue seems to weaken considerably in the still shot! so it's worse while the captures running. Will try another VCR tommorow. Regards Parsonic.

[GrassValley_BH]

Likely the shift was in the original source, but it's worth trying another VCR if you have one.

[parsonic]

Well Brandon you were right. It is the tapes. See attached screen grabs. I know the quality is poor :a) because these are from my old Panasonic J35 VCR (set to edit mode) but they show my blue tinting problem and :b) I captured with everything at default settings with all filters etc. turned off, on the ADVC300. The last shot is with the saturation at about 10% and this tinting is still stronger than anything else in the shot. I can only assume that in the ten years or so that I've waited for the technology to become this good that the tapes have deteriorated in the mean time. Now what options are left? I have read that some editing software can colour sample a problem area and correct just those areas. Can Edius do this?

[GrassValley_BH]

Yes, the White Balance filter in EDIUS should easily correct that blue tinge. Download the demo and give it a try - it'll run for 30 days, which might be enough time to fix everything you need to... not that I don't want you to buy it... :)