We just did the same test on a NTSC GH2, same result. Does this happen only with 320? Or is it possibly a problem 'going up' to other ISOs as well? Will keep testing.
I get the strange feeling there is a potential shutter problem as well as the iso prob mentioned above or something we're doing with the hack is playing up with the gh2. Can someone confirm/ test 1080p24H on say flourescent strip lights or bus number LEDs - I was shooting today buses going by at 100 shutter (normaly no probs - PAL land) but in the LCD I could see flashing - as was confirmed by the recording, then I went shifted the shutter down, recorded at 60 shutter - everything fine, went back to 100, and everything was fine again. Strange indeed. I think I remember seeing this anomallity in my stock GH2. More tests I thinks... I was on manual. [*Setting tested was my GOP3ILLA patch]
Unless I understand you wrong, afaik that is normal with all cameras? If the SS is not in sync with whatever flourescent lights you are recording, you get the flicker effect. There's even some plugins for post that specifically are designed to address this issue.
@starstuff Im very aware of the shutter problem and how you should align it to the neccesary country lighting/hz whatever. Most flourescent lights should be in the 100Hz range, bus LED lamps should also be around 50. So 100 shutter should be suffice. However, I experienced from switching on recording at 320iso, seting to 100 shutter constant flickering, I then switched to 80, then 60 before it stopped, I then returned to 100 and it had stopped flickering. Something isnt right and tomoz Im going to repeat the tests.
I get flickering from my television (a samsung LED), and I've encountered similar issues with projectors f.i. (in PAL-land). Actually when I found a shutter speed setting that did not make the tv-monitor flicker, I got severe flickering on everything else from the light from the television. Maybe that makes sense to someone, I found it wierd.
Flickering is a bit random though, for me too - sometimes some shutter-speed setting produces bad flickering (affecting the whole scene) and sometimes not..
The good news is that it's normally pretty easy to spot from the display. One can then work around it by switching settings.
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Edit: on second thought, flickering from the television makes sense if it's, say 60 hz or something like that. (a 1/60s shutter speed would then counter that, but perhaps produce other problems with other light sources..)
One has to remember to take care in a scene with complex artificial lighting though.. Even faint light from a source which produces flicker can make it appear in unexpected places in a shot.
I guess many of the phenomena could be explained by light leakage, making it seem like there is an unstability in the shutter.
However, the ISO issue above is clearly something else.
It leads a bit to the conclusion that pana started to join the club of those who think that public beta testing is a cheap and powerful instrumenent. Which it indeed is.. just with some side effects.. ;)
Hmm... Very strange indeed. We will need more repeatitive testing for this strange ISO issue. It's as if the ISO function state does not always toggle, but manages to update the display to read the ISO values correctly. Maybe the times ISO320 is noisy may actually be setting it to somethings internally different like ISO640 for example.... WTF over...This is a panny issue no doubt. It seem like their programming for this is an issue. fucking bummer....
Its weird I thought I read somewhere that they made the 160 multiples as they would be the best case regarding noise. It seems the opposite is true, unless you shuffle back and forwards first.
I played around drifwood's 178Mb GOP1 setting, it looks really nice however it seems the claim from some people is right - could be found some remarkably artifact in dark area.
So, I tried to improve that problem w/ colour profile setting. - smooth profile - Contrast, sharpness, saturation, and noise reduction are set to '-2'. - White balance and temperature is adjusted to around 6500k. - +3 exposure.
This setting tried to remove gamma from AVCHD-intra... I mean I tried to have 'Linear' gamma. I applied gamma(2.2) in post process.
It looks mid to dark area had been much better. Of course 8bit dynamic range is not enough to use linear gamma, mid to hi-light tone was messed.
This test sounds silly but hopefully some people might be interested. ;)
I just assumed that since traditional digital video cameras are ISO 320, that it was a good default ISO to work with. Figured the reason for the 160 ISO group was to stay on this multiple.