GH2 What causes this color banding in the sky?

I am having similar banding issues but in the background of this shot. I used similar settings as the chemtrail video . What is up?
 
I think the banding seen is fairly typical, I've had similar results using subjects that have gradual tonal gradients (skies, lens flare, etc).

Another factor might be the codec's decision to drop detail. Check out your .mts clips in something like Mediainfo - is the bitrate reported anywhere near 24Mbps? If all you're filming is sky and vastly underexposed background it will barely be using the codec's full potential. I did some sky timelapses and found the bitrate tended to top out at 0.6Mbps. Banding was present in all the clips.

Care must also be taken if you're pre-processing videos for encoding. Denoising or degraining will often bring out banding, especially in grainier subjects. One of the reasons banding is so prevalent in Youtube and Vimeo uploads is because many people don't take the time to pre-process their video, and upload them to such video sites, warts and all. The encoders over at these sites (often not encoding with optimal settings to reduce the requirements for decoding) then eat the grain, especially at lower bitrates, and you're left with shifting blocks of pixels where the grain once was and banding. H264's in-loop deblocking filter can only do so much..

tl;dr GH2 is still amazing, but you should consider the possibility of debanding in your post production stage!
 
mediainfo says the original MTS was 12.5Mbps. I checked all my other video clips and almost all of them are below 24Mbps. Seems like even though I have the video set at 24H it is not recording at that bit rate
 
This type of color banding (aka posterization) is different from what is often described as GH1/2 low-light "banding" (horizontal or vertical noise patterns). The effect seen in the sky is the result of setting your exposure low enough to avoid overexposing the white trails. This forces the camera to encode the darkening sky with only a few bits of the available 8-bit color depth of the AVCHD codec. As others have suggested, it may be possible to disguise the posterization with post-processed dithering, but it is an inherent limitation of the low-light properties of the camera. Increasing the bitrate would not significantly improve the image, since the problem is a lack of tonal range at low exposure levels.
 
it might be the choice of "Film Mode" in combination with the white balance settings. All banding issues I had had been due to bad film mode settings. What film mode did you use to shoot the sky?
 
I use Nostalgic because it seams to be the flattest setting of the GH2. I'm not 100% sure about this. People don't like the more noise you are getting from nostalgic. Plus it adds a sepia look to the highlights. Specially on skin tones you get a nice, smooth highlight roll off. Smooth might also produce better results for gradients than Cinema. For white balance I use 5200k to 5800k for daylight. I always use the kelvin dial to do white balance.
 
Just tried it; cinema mode, all settings at zero, tried w NR at -2 and also at +2. Very noticeable grAdients in both. Not really thrilled with it.
 
I dunno, I shot a similar scene a couple weeks ago with my GH2, and there's absolutely no banding.
Here's the raw MTS file:
http://www.sendspace.com/file/l550mt

Nothing special with the settings. Standard mode, sharpness -2, NR -2. I don't remember exactly, but I'm pretty sure the ISO was 160. 14-140 lens @ 14mm.

This is bizarre. But then again, what else is new? Could there possibly be different firmware in these cameras?
 
Barry, I emailed Panasonic and they replied that they were forwarding it to Tech. Maybe you can use your star status and check as well to see if they have a solution for this.
 
Just wanted to post an update. I bought a Variable ND filter and the banding issue seems to go away at certain levels of ND. I don't have perfectly clear sky today so I can not recreate the original test video. I just went out to shoot some sky shots and there are to many clouds right now, but in the blue areas of the sky the Nicna fader nd at the levels of minimum all the way up to level 6 showed no banding, from 7 to maximum there was banding.
Set at f4/160s/iso160 auto focus/nostalgic
 
Hello everyone,

I'm having this exact same problem in some shadows and defocused areas. Instead of soft gradients I'm getting these ugly bands similar to the sky in the OP video. Let's see if we can find some combination of settings/filters to minimize the problem because otherwise this camera is awesome. I'm going to do some tests and keep you posted if I find something interesting.
 
Panasonic acknowledges the problem

Panasonic acknowledges the problem

Panasonic Japan has confirmed to me that they are aware of the colorbanding problem, but can not say if or when it will be addressed by means of a firmware update.

But as far as i know these people -> if they can't solve it, they wouldn't have answered my mail in the first place, so having good hopes for a resolve.

I see that the banding is also outputted through the HDMI output, so that renders the camera useless for any kind of broadcast whatsoever at the moment, and confirms that it has nothing to do with the AVCHD codec or compression.

Can i assume that the AF-101 does not exhibit this problem?!

Such a shame of such a beautiful camera with such a gorgeous picture...
I think we have to be patient...


Martin Beek.
 
can anyone please try to test whenever this problem occurs? is it the sky? lens? what to avoid ?
any precise info would help a lot at the moment, thanks.
 
I don't think there is a way to avoid it. If smooth gradients are confronted anywhere in the picture, they will appear as "banded". Blowing or crushing such areas only means that you are removing the gradient, so that's not a real solution.
It's a interpolation error that Canon and Nikon seem to have solved. I can see it in some of my 5Dmk2 shots too, but only if underexposed.

Martin
 
You must log in or register to reply here.
Back
Top