'Terrible' banding artifacts from DVX100B?

artist

New member
To the Moderator:
I've read around for a while on this topic but still not satisfied about the answers I've found.

I understand about the lossy DV compression in DV camcorders, but I'm mystified as to why this effect did not occur in my previous camera - the Canon XM1. The effects are spoiling so much of my footage and tweaking the scene file has at best only partially hidden the banding with the introduction of unacceptable noise. Has anyone else encountered this problem?

My question is simply - Does that look like what you'd expect or does it look like something wrong with the camera?

Please have a look at an example of banding artifacts here (it's a small quicktime movie):

http://tonycaunce.co.uk/The Meal-Daylight-H.264 300Kbps Streaming.mov

This is just the way it looks on my flat screen monitor and in FCP. On the CRT broadcast monitor it's not nearly as bad but still overall it's completely unacceptable. This is also the way it looks in the camera viewfinder and LCD as I'm shooting. I'm doing some tests for an indoor scene.

If it weren't for the fact that I've not noticed this problem until using the DVX I'd be able to accept that all DV is limited in this way. The Canon, though it produces a far less crisp and detailed image, didn't show a hint of banding and I might have to revert to using that, but it seems silly, or perhaps I'm getting more critical about my image quality. Also I've seen footage claimed to have been taken with the DVX with blank walls in the background and there's no banding or noticeable noise so how do they do it? Is it all down to a lot of hard work in post-prod? I've read about the Ramp effect in AE and some other techniques but surely that kind of work is a last resort?


Any light shed on the matter would be greatly appreciated.

I used these settings:
25p - altered scene file as follows:
v detail freq: thin
experimented with moving the vertical detail, detail and detail coring up and down
detail level to full and detail coring to minimum gets rid of most of it but introduces too much noise.
Master ped: -4
Everything else as was in factory settings.
I've followed various recommended settings.

Maybe I should add that I'm using a PAL version.

Tony
 
Try raising your master pedestal to 0 at least, or +1. Increase your exposures to get better saturation of the sensor and more data in the image to work with. You can always back values down and increase contrast in post.
Very flat contrast value scenes like your sample are pretty much going to show banding over large areas on less than 10 bit displays or encoding though. Convert your original footage to a 16 bit per color intermediate format like Cineform for editing. Low bitrate H.264 and 8-bit AVCHD are notorious for this.
 
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Banding issues remain

Banding issues remain

Razz16mm,
Thanks for the suggestion. I did try this and more. I'm afraid that twiddling with settings is merely putting a cosmetic veneer over what looks like a real core problem with the image on this camera. I can't find any help at all on the web for this problem. It seems to be getting worse, when comparing footage I shot a year ago to looking at the same view today through the camera. Just can't get rid of those streaks. I've included two more links to clips, - the first shows some more instances of the effect in the Panasonic, the second shows the same scene captured with my old Canon XM1. Although the image will obviously be less crisp in the Canon, this is what it should look like. The lighting is a bit subdued, but this is just the background, the talent would be lit from above with a soft but fairly strong light. Anyway this is a bit beside the point. Could this be an in-camera software issue? Can it be repaired. No-one else seems to suffer from this to the same degree.

http://www.tonycaunce.co.uk/Halogen-light-tests1-H.264 800Kbps Streaming.mov

The Canon:
http://www.tonycaunce.co.uk/Halogen-light-tests2-H.264 800Kbps Streaming.mov


Anyone got any ideas on this?
 
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