first lens selection help, filming low light with Panasonic GH3

Hello I'm new here and in need of some advice..

I'm upgrading to my first interchangeable lens camera from the Panasonic LX7 (which is great). I've decided on the Panasonic GH3, but I need help with the lens selection.
I film a lot of live concerts so most of my use is in low light (stage lights in a darker venue) and at close to medium range.
The LX7 works perfect for me with low light performance and wide angle, i would like the equivalent performance in the GH3. I rarely use the zoom of the LX7.
LX7 specs here: http://m.dpreview.com/reviews/panasonic-lumix-dmc-lx7/2

I'm thinking the Olympus 12mm/f2 is my best bet..? I'm worried about the lack image stabilization though. Stabilization is built into the LX7. Most of the time I film hand held, and try to keep as steady as possible. Will the lack of stabilization in this lens be a big problem? (I could fix in post editing I suppose..?)
My other thought was the Panasonic 12-35mm f/2.8..but I worry if the f/2.8 will be sufficient?

The camera was big purchase, i want to get the right lens. Also less important is I do take pictures and would like a minimum of lenses to carry around but will work nicely for everyday pictures.

Thanks for all your help!

I'd think that a 12mm would be too wide for the kind of thing that you're doing. I have a GH2 and I've been doing a lot of stills at musical events and have been using a 25mm f1.4 Panasonic lens, which is nice and fast and despite the fact that it isn't reputed to be all that sharp wide open, the images I get from it look pretty good to me. I think that photos of people don't really need to be as razor sharp as that of other subjects. I also use an old 50mm 1.8 Nikon film era lens with an adaptor when I want a little closer view. Of course with this old, adapted lens everything is all manual as there isn't any connection to the aperture with the camera so program or aperture priority isn't possible. Manual focus is necessary as well, but I end up focusing manually with the Panasonic 25mm as well because when I'm shooting musical events the light is usally low enough that autofocus doesn't work very well anyway. I get understand that video shooters often use manual focusing... For my still photo stuff, I have to say that these two lenses serve me really well for low light music photography stuff. The Panasonic is a beautiful lens but the much cheaper, old Nikon is very nice as well. I can only imagine that these lenses would be even better for this sort of thing on the GH3 as I think that the noise/ISO is probably stop or two better on that camera than on my GH2.

One thing that I'll add here is that more important than IS, Id say is a monopod. A tripod is of course going to be too cumbersome to take into a typical venue and pretty hard to move around with. A monopod though is just the thing for stabilizing a camera just enough to use slow shutter speeds... or in your case to shoot smooth video.

If you can afford it, the 12-35 f2.8 is a great lens to use for filming concerts. It will give you more range than a fixed lens and hence more variety of shots. I use the GH2, GH3 and GX7 for the same type of work. Of these the two more recent cameras are best in low light. Generally 1600 ISO is the limit for me. We also use the Olympus 45mm f1.8 and Panasonic 20mm f1.7 for this purpose, the latter usually on a static tripod at the back of the hall giving a wide shot. The 45 is often used to dodge around in front, to one side or actually on the stage depending on the type of performance. Here I use a monopod for stability as suggested by another poster. This works well for me (I have a lightweight Velbon) and because the monopod extends well over head height it can be used for high as well as low shots. Of course it is best to have at least one more static camera if it is important to capture a whole set. For sound we use a separate recorder hooked up to the mixing desk and sometimes a separate stereo mic for ambient sound to mix in. Overall, a lightweight setup that works well.

I think looking back on what f/stop you'd used most of your LX7 would offer you a better guide on your new M43 lens. Never forget the higher ISO capability of GH3 would allow you to shoot with a slightly slower lens.

filmy wrote:

Basically I used the LX7 at f/1.4 fairly close to the stage for the most
part at a low ISO setting.

1. Do you think the Panasonic 12-35mm f/2.8 would offer equal low light and
   wide angle quality? (Catching the whole band in the shot)
   I guess i can use a higher ISO with the GH3 and that will offset the slower lens?
2. Which prime lens would offer the same performance as the LX7? the 25mm f/1.4 panasonic?

I've been reading here a lot but I'm still new to this.
Thanks!

Ps. I do use an external recorder for audio

LX7 is a fixed lens P&S camera covering the most using focal length between eq 24mm (Wide angle) to 90mm (short tele).

GH3 is a system camera and it could use any lenses from native auto focus lenses from Panny (some have OIS) and Oly, a few from Sigma and one from Tamron. Through a few $ adapter you could also use nearly every piece of old or new legacy manual focus lenses from any brand. So, theoretically you have unlimited lenses of any focal length / speed to chose. The one your particularly have interest, 12-35 is a eq 24mm to 70mm and is very similar to LX7 specially on the wide angle side (allow you to take whole band in a shot if LX7 could).

On the surface, LX7 is having a f/1.4 ~ f/2.3 lens whereas 12-35 of GH3 would be fixed at f/2.8 (so is slower). However, LX7 is using a 1/1.7" sensor vs GH3's (all M43) much bigger sensor, the high ISO performance of GH3 is better than LX7. Just similar to the comparison between FF vs 43 (FF is 3.84x bigger than 43), GH3 is 5.23x bigger than LX7. Although I personally not care about DxO's sensor rating, it suggests that the sensor rating score of LX7 was 50 whereas that of GH3 was 70.

Due to a much better high ISO performance of GH3, the ability to obtain cleaner image could offset the faster lens advantage of LX7. If you would consider Oly's 12mm f/2.0 (same eq 24mm wide angle), it would further narrow down the speed difference with LX7.