Thank you peternap.

Yes I realise I'm asking for the best of all worlds... low data rate whilst achieving low noise at high ISO, but at least my subject is pretty static, so there are no rapid changes effecting large parts of the image. Would this therefore better suite a long (6 or 12) GOP structure? Do long GOP structures have a negative effect on image noise, or blocking artifacts?

regards

Don't know how much noise is your limit; I shot a lot of concerts (not professionally), and the lens that I've used most when I had the GH2 was the Panny 20mm 1.7. With good stage illumination (small stages, not anything fancy) I could use it in f/2.8 and ISO between 800 and 1600; the noise was ok, and no problems with DOF (musician in front always in focus, the drummer in back slight blurred but recognizable). In smaller places like bars, couls be different.

At the time I was using the Sanity 5.1 patch, much better quality than stock firmware, with very reasonable file sizes. Spanning was not reliable (I did not have the correct SD card at that time), but this info you could get in the Sanity thread here in the forum.

Well, then you need zooms. Since you said that would be working with smaller apertures, one lens options would be the 14-42 II from Panny - it is much better than the kit lens that comes with the GH2 (the first version), probably could get one used very cheap, and have a good OIS. I've recorded this with it - footage right from the GX7, except for a little EQ in audio, at ISO 1600 if I can remember well (not great footage, I've bought the camera about 6 hours prior of this).

A good manual option could be a Minolta MD 35-70 f/3.5 - bought one some time ago, never played much with it, but is a VERY sharp one.

But I guess that people here could have better suggestions.

I think you're going to be disappointed with the GH2 in low light

Sorry Guys, I just cannot justify the expense of two GH4's. I only wish I could! My 5D mlk II's did a grand job shooting video at F4 and either 1600 or 3200 ISO, and I know that the 5D mk II line-skips to record video, only capturing every third line from the sensor. Both cameras are from a similar era sensor technology-wise, and a 4/3 sensor has a 2x crop factor, so one quarter of the surface area of the 5D.

This would mean if the native sensitivity of the actual CMOS were similar between cameras (I need to look this up), then the GH2 would only have a minor disadvantage in light gathering capability during video. DXO shows 5D as having low light ISO of 1815, with the GH2 as 655. I'm not sure if my maths is correct, but if you divide 1815 by 4 (sensor surface area difference between sensors), you get value of 453, not 655 which indicates the GH2 sensor is somewhat more sensitive per square millimetre than the 5D mkII's sensor.

Upshot is I cannot afford to invest more than about £800 for two cameras, so I need to look second hand. I want to shoot without 30 minute restriction, so any UK camera would need to be hackable. I don't want to go to APS-C, but I have looked at 1" sensor cameras, and smaller still, but surely the GH2 should have more light gathering capability than a 1" sensor?

regards

yes mrbill, my glass is REALLY slow (other than my 20mm prime), as I sold my 16-35 L 2.8, 24-70 L 2.8, 70-200 L F2.8, 50 F1.4, and 100 F2.0 macro with my two 5D mk II's when I stopped shooting weddings.

Basically all I have now is strictly consumer grade glass for the GH2. I don't want to really shoot any wider than F4 though because of DOF limitations at equivalent focal lengths of 100mm full frame.

This is only a hobby for me, I'm not a professional. I had looked at camcorders, but unless I go for a semi-pro model worth a grand, then camcorders have such a tiny sensor, I thought I'd get better image quality/sensitivity from a 4/3 DSLR sensor. I used to have a Sony HDR-FX1E a few years ago, and it was great for a pro-sumer video cam.

So the GH2 has massive fixed pattern noise? I guess I'd better test some patches and see what I can do!

Thank you for your input, I really appreciate it.

So do I need to bin the idea of a GH2, and start looking at a semi-pro vid cam set up instead, like Sony nex VG10 or VG20, or a Panasonic AG-AF101? I can probably do £450 for a second hand body, but not twice that.

P.s. The gh3 produces a very nice image if you don't start dialling down contrast settings in an attempt to produce a log-like profile. Leave the settings alone, shoot standard or natural, and you'll make nice pictures.

Another great Hack would be the Valkyrie 444 series from bkmcd, those have a ood low light performance and work with about 50 mbit/s in 25p mode ;)

And definitely check out those old but fast manual 28mm, 40mm and 50mm lenses you can find on auction sites or at local second hand traders. you need them!

I've now tried Sanity in low light at high ISO's, and conclude that at ISO 3200 noise is just too excessive. I don't believe the best codec in the world will change this situation... it seems to be plain-old sensor noise due to being driven at excessively high gain.

ISO 1600 seems quite acceptable for my amateur purposes; maybe with just a little correction in post. I'm not noticing fixed pattern noise in the image anywhere though; just random, speckly, high-frequency noise. When FPN was mentioned earlier, I was dreading I might find horrible constant gridding or vertical lines present, but they are just not there on this particular camera example as far as I can see.

At 3200 I see spade-loads of larger red/green speckles like you'd see when pushing ISO too high in a still picture on any digital camera, and of course the dynamic range really starts to suffer at this point too.

I could try another couple of patches at 1600 to see what they look like, but I think the results I've got with Sanity are really fantastic considering I'm clearly running the ISO as high as I'd like to go with this camera/sensor.

If F5.6 is still too slow for me, then I can look to buy the odd manual F2.8 zoom with an adapter. I quite liked the Tamron 28-70 F2.8 using it both on my original 5D, and my 5D mk II's also.

At the end of the day, I was trying to find something to do an amateur shoot of musicians, that would give better clarity, dynamic range, and signal to noise ratio than a consumer video camera. I feel the GH2 does manage to achieve this for me at just a couple of hundred quid per body. I don't see how I could practically better this without at least doubling that spend, and as far as I understand, the GH3 isn't hacked for continuous recording beyond 30 min limit, which I need.

thanks to all for your help.