GH2 why do i get THIS ?
- Thread starter roei z
- Start date
Matthew P
Well-known member
Can't see it very clearly, as the file has been heavily jpeg compressed. Would be handy to get a high-res view of it. Try uploading to imageshack or something.
Anyway, I assume that what you're seeing is 8-bit colour banding (how many camera problems can be described with the term 'banding'?!), which affects the GH1/3 too I believe, but it seems to really stand out on the GH2. I'm not sure whether the GH2 is just more severe with it, or whether its compression doesn't mask it, but either way I don't think there's a proper fix for it. You might try adding some kind of threshold blur, so that the bits of the picture which don't have much detail get blurred even more, resulting in the bands getting blurred too.
Anyway, I assume that what you're seeing is 8-bit colour banding (how many camera problems can be described with the term 'banding'?!), which affects the GH1/3 too I believe, but it seems to really stand out on the GH2. I'm not sure whether the GH2 is just more severe with it, or whether its compression doesn't mask it, but either way I don't think there's a proper fix for it. You might try adding some kind of threshold blur, so that the bits of the picture which don't have much detail get blurred even more, resulting in the bands getting blurred too.
The gradient posterization on the right side of the urn is likely due to the limited tonal range of the chroma channels in the AVCHD encoder. The 4:2:0 color depth of the encoder samples the chroma channels at only 960x540 with an 8-bit range at best. As there are few edge details in this part of the image, the codec will treat it as a low-resolution area and allocate minimal bitrate to encode it. This will force it to use coarse quantization on the chroma data, resulting in visible banding of subtle color gradients.
You may see better results in shooting this kind of subject matter with the MJPEG encoder.
You may see better results in shooting this kind of subject matter with the MJPEG encoder.
roei z
Veteran
hmmm.. thanks.
i didn't realize this codec limitation phenomenon was so well known and dangerous, as i have many shots this doesn't happen.
it looks like very certain situations can make it 'appear'.
i just need to know how would i try to avoid them.
what's so particular about this shot ?
the specific white to dark areas? this makes the color banding more apparent?
i have many other shot that SUPPOSE to produce a limited tonal range but the color banding is not there.
i didn't realize this codec limitation phenomenon was so well known and dangerous, as i have many shots this doesn't happen.
it looks like very certain situations can make it 'appear'.
i just need to know how would i try to avoid them.
what's so particular about this shot ?
the specific white to dark areas? this makes the color banding more apparent?
i have many other shot that SUPPOSE to produce a limited tonal range but the color banding is not there.
photonashville
Well-known member
Adding very fine amounts of monochrome noise is the standard fix for posterization in still photos. It can work for shots like this as well by subtly smoothing the posterization effect.
Posterization is common in any image, still or motion where a large area with low bit rate (not shooting bit rate but the color bit rate) has gradients of tone that don't differentiate themselves.
Posterization is common in any image, still or motion where a large area with low bit rate (not shooting bit rate but the color bit rate) has gradients of tone that don't differentiate themselves.