Luminous Landscape Forum

Equipment & Techniques => Motion & Video => Topic started by: rainer_v on December 31, 2011, 01:42:33 pm

Title: strange artefacts with gh2 movies
Post by: rainer_v on December 31, 2011, 01:42:33 pm
did anybody of you see this kind of artefacts? most likely my GH2 is defect ... what do you think?
in all iso, with original and with hacked fw in 720 and 1080.



Title: Re: strange artefacts with gh2 movies
Post by: bcooter on December 31, 2011, 02:13:39 pm
Ranier,


I don't know about the gh2, though some videocams produce a progressive (faux single frame) setting from post processing of the interlaced footage and some don't.

Yours looks like your set on interlace and the result you see (those little black lines) is called combing.

IMO

BC
Title: Re: strange artefacts with gh2 movies
Post by: fredjeang on December 31, 2011, 03:51:28 pm
Ranier,


I don't know about the gh2, though some videocams produce a progressive (faux single frame) setting from post processing of the interlaced footage and some don't.

Yours looks like your set on interlace and the result you see (those little black lines) is called combing.

IMO

BC

It was also the only thing I could think of.

But it seems that Rainer is experiencing it under every conditions, with all possible camera set-ups.

I'd like to know also because I'm missing a point there.

To me it's not a camera defect, it looks really like combing, but how could it be if in progressive mode?  
And like that, right-out the camera?
Title: Re: strange artefacts with gh2 movies
Post by: rainer_v on December 31, 2011, 05:22:04 pm
yes it appears in all settings, sizes and with the original fw as well as with the hacked one.
Title: Re: strange artefacts with gh2 movies
Post by: Christopher Sanderson on December 31, 2011, 07:03:11 pm
since it appears to be tooth combing, my guess is that half the resolution is missing...a fried sensor chip?
Title: Re: strange artefacts with gh2 movies
Post by: Bern Caughey on January 01, 2012, 10:45:55 am
What program are you using to play the footage?

Has it been transcoded?

Are you shooting NTSC, or PAL?

My guess is it's a post error, not camera.
Title: Re: strange artefacts with gh2 movies
Post by: tho_mas on January 02, 2012, 06:49:38 am
My guess is it's a post error, not camera.
that's how I see it, too. Looks like unintentional deinterlacing of progressive footage (wrong deinterlacing respectively).

Rainer... here is a QT Plugin from Panasonic that enables QT to playback MTS files natively (it's a useful plugin anyway when you use a GH2): https://eww.pass.panasonic.co.jp/pro-av/support/desk/e/download.htm#avccamip

Install it and playback a 24p (or 720p) file. You should use QT 7 for playback - not in QT 10, as QT 10 automatically deinterlaces interlaced footage.
This is just to take out any conversion errors out of the equation.
When the file looks okay your issue posted above is most certainly a software or workflow error.

Alternatively you could as well use "ClipWrap" ( http://www.divergentmedia.com/clipwrap ) to convert your MTS files to *.mov. Output format should be set to "Rewrap"... to simply rewrap the files from MTS to MOV without altering any movie parameters. Again, converted movies should be played in QT 7.


Title: Re: strange artefacts with gh2 movies
Post by: fredjeang on January 02, 2012, 11:24:04 am
I also have the feeling from the beginning that it's not a camera defect.

But precisely, if it's not, what's happening to Rainer shouldn't happen and show the mess that's the norm in this industry.
Clutter that obliges to loose time, trying to understand what's happening, require to third-party mini softwares, plug-ins of all kinds and put people into nerves and confusion etc etc...

Amazing indeed !

Coot talked about the wild-west, I'm not sure if in fact we are not yet into the stone age.

I'm still amazed how this industry users tolerate such a ___ from our manufacturers.


Title: Re: strange artefacts with gh2 movies
Post by: rainer_v on January 02, 2012, 07:50:48 pm
it appears in windos playing back the original data as well when they are with 5DtoRGB translated to prores422.
i dont get any information withoiut these artefacts out of the files. anyway ... i played around with the new magiclantern hack for canon fw 2.0.9 and this gives similar bw and lokks very good also. i will give back the gh2 to amazon ...
Title: Re: strange artefacts with gh2 movies
Post by: Morgan_Moore on January 02, 2012, 08:06:49 pm
seriously - this is a post problem -

I guess the 'pull down' is wrong

nothing wrong with the camera I am very sure
Title: Re: strange artefacts with gh2 movies
Post by: fredjeang on January 03, 2012, 05:42:18 am

nothing wrong with the camera I am very sure

Probably nothing wrong with the camera indeed, but if I was in Rainer's situation, I'd do the same thing: return back the camera and back to Canon.

Those things, shouldn't happen.

And we have very little time and patience to deal with those sort of problems, whatever the source is.

I really like the GH2, mostly because IMO, it represents what the evolution of technology is driving us to: smallest and smallest equipments but each time more powerfull and versatiles.
But then again, the GH2 is a consummer product and if there's a lot to like about it, there's also a lot to complain too, starting with quality control.

I'm fed-up of those equipments made in China or Taiwan at very low cost, because most of the time there are issues. (not talking about the human exploitation that's involved behind).

The hack: Tho_mas hacked his GH2 with the same that I did. It worked for me, it didn't for him, with the same settings. But a different hack worked for him, and maybe wouldn't work for me.
It's all about guessing and hopping it's gona work. No thanks !

Panasonic messed-up with HDMI (mainly I think for strategical reasons). Cameras also have an annoying banding in some conditions.

What else? Oh yeah, the Bloom's hack. He said that because there are no cards currently totally reliable, it freezes after X time of recording. Yes, details are better than with expensive pro cameras, wich is just nothing less than impressive, but if you freeze, what's the point?

So yes, the GH2 is capable of delivering the highest quality file in a small package, but if things go that way, I'd rather sacrifice also the compactness and back to bigger Canon with the old heavy and big cage because I don't want to mess anny more with gear that aren't totally working or that aren't totally ready.
The magiclantern hack for the Canon is a great option and will bring the Canon very very close to what the GH2 is capable of (except for moiré). But at least you don't get those kinds of issues while viewing the footage, or cameras that work for some and do not for others. With the 5D2, you won't ask yourself at higher isos if you could remember the right settings so you don't have the banding in underexposed...

I'm watching closely what is happening and probably won't buy any more Panasonic camera until they got a more serious factory control because it seems to be a weak point there.

More generally, buying low-cost made in China is not a that great idea unless the company demostrate they have a really strong quality control. For the material I've seen over the internet recently, the GH2 is failing, there is a problem, CC totally unconsistent.


I haven't done so far a truth session with the hacked, because testings I'm doing at home are working perfectly, but in the real world stress, it could be another story...if it fails (freezes), I'm going back to Canon as my main video-camera and would keep the GH2 as an HD note-book.

We can't rely on unreliable products.





Title: Re: strange artefacts with gh2 movies
Post by: Morgan_Moore on January 03, 2012, 06:47:10 am
Im sure its a simple solution like unchecking the 'de-interlace footage' option somewhere in the transcode path

Being neither a GH2 Owner or knowing Rainers workflow I can't comment further.

Maybe rainder should head over to DVxUser or suchlike for specific Panny advice..

Of course all this consumer stuff is basically crap, I have only two things I trust my D3 (for stills) and my SoundDevices 702 recorder for sound and maybe my EX1 for vision

The 5d is impossible to monitor, the GH is tiny and fiddly etc etc

But these flawed tools do some pretty amazing stuff on amazing budgets

Everyone of course has the option to hire a DP an AC and a DIT with an Alexa package.. a combination that Im sure works pretty well :)

S