Dpreview have posted some GH2 samples taken with the 14mm f/2.5 lens. Some of which are excellent and some of which look very processed and lacking detail. However the high ISO shots look much the same as others that have been posted elsewhere, i.e. very promising.
There are already complaints on the forums about how these are not very good. I'm at a loss to see what the complaints are about. In a completely unscientific test I took two 500px square chunks out of a Dpreview sample and one of my Canon 7D shots, both at ISO 3200.
I'm presuming the GH2 is an out of camera jpg as is my 7D shot so a rough comparison is possible. I can't really see any problem with the GH2 shot. All the others I've seen look very good and stand comparison with shots I've taken with my Canons.
The shots I've seen at 6400 and 128000 from the GH2 are on the border of useability, and its certainly not something you would use out of choice. But then the same applies to both my Canons. For the ultimate in low light performance none of these cameras are as good as as a D3S or a Canon 5d Mk II, but they are certainly a vast improvement on on the 4/3 and APS-C sensors that preceded them.
We all seem to have got very greedy very quickly. It seems we are not satisfied unless we can take noiseless pictures in total darkness.
The following is from a picture I took at a wedding in 2004 on a Fuji S2 Pro at ISO 1600.
The S2 Pro was a very popular camera with wedding photographers at the time and was generally regarded as being pretty good for high ISO noise. As you can clearly see, things have moved on somewhat.
However we all managed, and despite some notions to the contrary those of us from the stone age did manage to take pictures in low light before the arrival of modern cameras. We even managed in the days of film when anything over ISO 400 had serious grain.
Yes its great to be able to take pictures hand held in low light and get a "clean" image. However I don't regret having to put up with situations where it wasn't so easy. It meant I learnt to use a flashgun to get natural results, I learnt to focus fast manual lenses in semi darkness and I learnt to anticipate and use the available light. All of these things have proved very useful and are techniques I still use all the time.
I have absolutely no problem with the high ISO performance of the GH2. If it proves to be as good in practice as the samples seem to indicate then I will be happy to use it as a "work" camera.