Horrible sensor output! Is it a bug in GH2 implememntation of AVCHD?
 

Yesterday I was so happy to got my new GH2 (PAL version). I have played with it, and I then I got this

http://www.aviangarda.eko.org.pl/pumping.mts

Please download (it is only 12MB) have a look at it and tell me what you think... An .mts file is untouched, straight out of the camera. Can you see this very strange "pumping" noise? What the hell is that??? The noise pulses like a heartbeat - goes up and down, up and down. Also the footage goes darker and lighter frequently. I've never seen it before on any cameras!

Am I having a broken camera that must be replaced or is it a bug in firmware..? Would somebody please help me by recording some darker scene at 1600 iso, underexpose about -2EV, using ExtendedTeleConverter mode and tell me if you get the same pulsating noise? My test footage was shoot at manual apreture and shutter, at 720p AVCHD and ExtendedTeleConverter mode was used, 1600 high iso, underexposed intentionally, as I was testing the camera.

I have done several more tests today. Of course I know: the higher iso - the higher noise, but this is normal and I clearly know that! What is abnormal - are these pumping! This cycling "pump" issue is really bad and is frightening me up. Why the noise level is going up and down in a fixed time pattern..?! When I have recorded the same scene with the same settings in MJPEG and AVCHD i could see the pumping occurs only in AVCHD, while MJPEG is free of that! In a MJPEG footage the noise is evenly dispersed across the whole image and roughly stays at the same level, is not pulsing/pumping at all. But in AVCHD it permanently pumps up and down.

Is it a bug in GH2 implementation of the AVCHD codec or just my camera?

Czecz, Waldi! I myself haven't been able to get usable footage from the ETC mode, either. It's very difficult to achieve sharp focus.

Czesc Patrik, good sharpness is another problem, but how about this pumping noise..?

What lens are you using? The 14-140 is only capable of so much, it is not a great lens. I suspect if you were using a Canon f/1.8 85mm your image would be much better. The sensor cannot make up for a weak lens.

I will be working with the 14-140mm, but I can't imagine that fully zoomed it would produce great images at 1600 ISO in ET mode. I think you might be expecting more than is realistic, but I could be wrong.

The thing that almost held me back from ordering the Panasonic is the poor lens choices. Use converter, fine, but then you're stuck with primes and no autofocus.

My Canon 40D shot better looking photos with an amazing Canon 1.4 than I'll probably ever get with any Panasonic lens, but I'm sure I'll be buying a converter at some point. You can't replace good glass with a great sensor. Both must be great.

Jeff, I am not talking about quality of the image or lenses used, but about noise that PUMPS up and down! If I would record an empty surface with no any lens attached it would be the same pumping issue at these settings. In other words - strange pulsating noise is what I am talking about. The frequent changes (like pumping) of noise and darkness/lightness is what it should be? Take a look at these tree trunks on the sides of the frame... Why it disappears in MJPEG but is easily visible in AVCHD footage? It has nothing to do with lens.

Waldi,

What equipment did you shoot with?

What were your camera settings?

What is your post process?


- Guy

I don't see the pumping. (do you mean pulsating?) It looks fine to me. I see grain. It's dark. Something is adjusting to meet changing light conditions as the tree moves, maybe. I don't know.

IIt just looks dim.

For as dark as it is, with the lens your using, it's fine. Your using a high ISO in full zoom in a dark setting with an average lens.

GH2, settings as in first post, no post processing, as mentioned above.

Yes Jeff, I mean pulsating (sorry for my English). You don't see it? Well, well, well... let me see it on a different computer, as it might be my player (VLC) that causes that pulsating or a weak laptop? That would be great if it is only a player issue. Anyway - many thanks for giving me a hand.

The quality of your video card will affect AVCHD playback, and I know exactly what you mean about "pulsating" noise. I get the same thing during playback in Premiere at certain times, because my video card is average.

Have no worry -- your source file is fine.

How does it look in your editing program before processing, I wonder.

I had wondered if maybe it was your PC or monitor.

Corey, that is useful information about the cards. I have ordered Sandisk, and avoided the cheaper ones just to avoid issues like this. $105 for 16GB is pricey, but hey, I feel better about it now.

I know the cheaper ones work fine most time, but still....

The file I've pointed to download is untouched, not post processed, straight out of the camera. I hope it was my laptop, I will check it out on a much faster desktop PC. Also I was using rather old 4GB Sandisk Extreme III SDHC card (the only one I had at the moment), so I will repeat my tests on a faster 16GB class 6 card and will preview it on a faster PC. Hopefully this pulsating wont show up again...

I am quite well experienced wildlife photographer and was always using SLR or DSLRs but I was absolutely shocked with this small mirror-less GH2 when I took some pictures. Outstanding image quality! Even in jpg format, so RAW might be only better. Video shooting is something relatively new to me, so I may make some mistakes, but anyway - I love this tiny GH2 and its video capabilities. Its sensor is awesome.

You have found the answer, my friend. Laptop, playing footage on an older card...sounds perfectly reasonable that it woudn't play perfectly.

Please let us know what you find out.

Sorry -- I actually meant the graphics card in your laptop, not the SDHC card.