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 remember there were few discussions about the ISO on other sites. Here's one from vimeo

Oh yeah...I don't know why I forgot about this bug. Thanks for jarring my memory.

Still...it makes me wonder about what's actually going on at ISO 320.

I don't think it's in any way related.

@driftwood

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.

Its only on certain lights it seems.

I tried my tests on a few manual lenses, @Meierhans what lens you try?

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.

---

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.. ;)

edit: ah yeah, used manual lense.

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.

hi,

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. ;)

Cheers,


Hiroshi

I don't use Vegas, but how did you remove that noise? And is there a way to do that in premiere?

f1lm3r,
Many use Neat Video for noise removal. Look it up.