goodgoings
Well-known member
I doubt there are differences between the Japanese or Chinese sensors or it is even a sensor problem, but do people who have the Japanese made Gh2 also have problems with posterization in areas of gradients?
Is there Posterization on Japanese GH2 also?
- Thread starter goodgoings
- Start date
is there anything wrong with your made in china one that we should know about? as for posterization isn't that just codec implementation?
Matthew P
Well-known member
ARE there any GH2s made in Japan? I think it's a bit unlikely that they'd have two factories, one purely for the home market, which is tiny compared to global. Aren't the models for Japan merely locked to Japanese, yet still made in China? Has anyone ever confirmed that their GH2 (or GH1) actually says "Made in Japan" on the bottom?
I think the question is whether the pre-production models had posterisation. From what I've seen from a quick look at pre-production footage, it DIDN'T have the banding. That's from a quick look, and I've probably not given it enough time, but it would be infuriating if it was actually true.
It's not a matter of it encoding 8-bit, I think, but rather lack of dithering the higher-bit signal into an 8-bit compression system. The GH2 does this very badly, and just chooses the "nearest colour", whereas, for example, my old Canon HF100 dithers that output for smooth gradients, and posterisation is, to the eye, none existent. Heck, even my old Panasonic TZ7 doesn't suffer from any kind of posterisation (0% aliasing as well, no idea how they manage that from a 6mp sensor). Mind you, it is MJPEG. Does MJPEG have the same posterisation artifacts that AVCHD does on the GH2?
I think the question is whether the pre-production models had posterisation. From what I've seen from a quick look at pre-production footage, it DIDN'T have the banding. That's from a quick look, and I've probably not given it enough time, but it would be infuriating if it was actually true.
It's not a matter of it encoding 8-bit, I think, but rather lack of dithering the higher-bit signal into an 8-bit compression system. The GH2 does this very badly, and just chooses the "nearest colour", whereas, for example, my old Canon HF100 dithers that output for smooth gradients, and posterisation is, to the eye, none existent. Heck, even my old Panasonic TZ7 doesn't suffer from any kind of posterisation (0% aliasing as well, no idea how they manage that from a 6mp sensor). Mind you, it is MJPEG. Does MJPEG have the same posterisation artifacts that AVCHD does on the GH2?
Did anyone have any luck minimizing posterization in GH2 footage by adding fine monochromatic noise? Right now I have three clips that I want to use where posterization just ruins the shot (too visible). I haven't tried the "adding noise" fix yet cause I'm in the verge of finishing various non video related projects and my hands are kind of tied right now. So I was just wondering if anyone had succeed fixing GH2 posterization in post. In any case I will try to process the aforemention clips before the end of the week and keep you posted.
roei z
Veteran
+1
i need a fix too !!! and a thorough tutorial on how to do it with AE
this is a bad problem and looks disgusting like a low color scheme on my PC...
goodgoings
Well-known member
Are you saying you have a Japanese one with posterization?
goodgoings
Well-known member
This guy says no banding, but I don't believe it.
http://vimeo.com/21530060
Or, are there any GH2 owners that have tried to find posterization, but haven't?
http://vimeo.com/21530060
Or, are there any GH2 owners that have tried to find posterization, but haven't?
Last edited:
roei z
Veteran
i had some sky shots that somehow 'made it through' with no posterization, so it depends on hidden factors, and still pretty risky.
not to mention all the OTHER various interior shots that failed.
I got posterization in heavily blurred backgrounds (close-ups with voigtlander 0.95 at f0.95), not so blurred backgrounds (medium close-ups at 2.8) and mildly blurred foregrounds (defocused profile shot of my girlfriend at f2.0). The thing is that a micro four thirds sensor with fast lenses can give you insane shallow depth of field when you need it but then you can get posterization in smooth gradients due to poor processing. This kind of defeats the purpose of shallow depth of field shots since you're going that route mainly for aesthetic reasons just to get this pretty anti-aesthetic effect. Having said that, until now, most of my shallow dof shots are posterization-free. Knock on wood.
As I said, most of my GH2 shots look amazing and I'm completely new to video (and kind of untalented) so the good results are completely down to the quality of the camera and the glass attached to it. But now, everytime I face a shallow dof shot or something with smooth gradients I'm scared of getting home, upload the footage into the computer and find that damn posterization effect. These last few weeks I've being feeling a bit of buyer's remorse. "Should I have bought a 60D and some EF glass and wait patiently for the 5d Mark III?" Questions like this torment my fragile mind on cold, lonely nights. When I bought the GH2 I thought that I was given up stills quality (which I hate, coming from an analog SLR, but was something I could cope with) in exchange of getting the best option for video on the 1000-3000 euros range. For the most part I think I made the right decision but I would like to have known in advance that GH2 video could have seriously potential problems like posterization and that weirdness that movement shows sometimes at 24p (and I'm not talking about the usual staccato thing that's to expect in 24p footage).
People on the verge of buying an HDSLR or HDSLR-like camera should take this into account: With the GH2 you are getting a much more cleaned and detailed video with unnoticeable moire and aliasing (not having to deal with moire was one of my main reasons for buying the GH2) but in exchange you'll face potential posterization and problems in panning shots or shots with a lot of movement in the background. Are these total deal-breakers? I would say no, but it should absolutely be written in red in your list of pros and cons.
goodgoings
Well-known member
AtticusD, thanks for your detailed response. I'm worried about the posterization, but haven't really thought about the weird staccato movement on pan shots. Is the staccato movement that bad? If you can't pan in a shot, what's the point in shooting a short with the GH2? Will the staccato movement distract enough where panning will be ill advised?
There's something weird in the way GH2 captures movement sometimes. It's more evident when you pan or when there's a lot of movement in the background. The first time I noticed it was in an aerial shot of a beach. There was a big portion of sea in that shot and with so many waves and ripples it seemed like the codec was struggling to capture all that movement in an eye pleasing way. I have seen so many examples of sea in 24p and it doesn't look like that. I was also following the 180 degrees shutter rule (24p - 1/50) so it can't be shutter related (unless the shutter is internally doing some ****ed-up thing on its own). Again the movement in most of my shots looks "natural enough" to me. In conclusion I wouldn't say that you can't do a panning shot with the GH2 (the sliding here looks good enough: http://vimeo.com/18345432 ) but you should be careful when doing it: Pan slowly and smothly and double check the footage on location whenever possible.
The main problem is that it's hard to know in advance if your shot is going to get posterized areas or weird movement of some subjects. What I would do in your case is try to check the hardware before buying (in my case that wasn't possible). Also take my opinions with a pinch of salt because I'm completely new to this game (writing wasn't enough for me anymore and I'm trying new storytelling media) and a pretty ignorant fella in any case.
I've just done a quick test on FCP to try to minimize this posterization ****. Filter: Add Noise (Amount:0,1; Type: Gaussian Noise (Film Grain) ; Monochrome ; Blend mode: Overlay ; Autoanimate). The posterization is far less noticeable now. It was an "offline" sequence using ProRes Proxy. I will have to try this in a ProRes 422 or HQ sequence just to be completely sure but the first results look promising. The workflow should be more or less the same in Avid, Premiere, etc but settings would vary depending on the shot I guess. And again, if someone with real expertise could shed some light into this matter it would be amazing since I'm completely new to video and I'm sure I'm missing a lot of important stuff here.
j1clark@ucsd.edu
Veteran
Posterization is most noticeable in areas where there is a smooth gradient of tone. The sky being a frequent offending situation. A wall with a 'smooth' tone and falloff would also be another.
I've attributed it to the fact that at some point the sensor is only digitized to 8 bits worth of value representation, and with compression, the problem is worsened. The same effect can be seen on LCD screens as well, as the less expensive, or older
LCD screens have a shallow bit depth.
"Dithering" can lessen the effect, which is ironic, in that most people want 'noise' out of their images... except in situations like this, where 'noise' covers this effect to some degree...
Searcher
Well-known member
@ Sun If you are referring to my not liking "made in china" then I should explain that the reasons have to do with human rights, the environment and globalism and nothing to do with the people or the fact they are foreigners. OH and sorry for the derailing- I wish I could contribute but I'm a newb.
Sun
Carbonite Member
I wish you had elaborated in your original post. The problem is all countries have human rights abuses. China is not the worst offender by far and why boycott a Company that has no history bad practice well apart from the battery issue.
As far as I'm aware the GH2 parts are all the same. It would be a mistake to alter the quality in certain markets. Panasonic is not that foolish.
I have had my GH2 for 3 1/2 months and I have not seen one instance of posterization. Maybe it exists in your camera, or maybe not. There are so many variables that come into play - how the picture is being decoded on your computer, what software is displaying it, the graphics card or chip and it's settings, even the computer monitor itself. Any one of these could be the cause.
To cut through all this muck, do this simple test. Take an HDMI cable and plug your GH2 directly into a TV. Play a clip that you think has posterization, from the SD card in the camera . If posterization appears on the TV, then it's for real. If not, then the problem is somewhere in your computer's "food chain".
To cut through all this muck, do this simple test. Take an HDMI cable and plug your GH2 directly into a TV. Play a clip that you think has posterization, from the SD card in the camera . If posterization appears on the TV, then it's for real. If not, then the problem is somewhere in your computer's "food chain".
Last edited: