GH3 GH3: Lens questions (Sigma 8-16mm and others) for storm chasing

[DerekPW]

Few questions:

A) Has anybody confirmed that the metabones speedbooster + sigma 8-16mm is a good combo on the GH3? Vignetting?
B) Anybody have any experience with any of these lenses and a speed booster on the GH3: Sigma(or Nikon) 18/200mm, Tamron 17-50mm (2.8), Sigma 17-70 2.8-4, Nikon 16-85mm?
C) Is the panasonic 12-35mm 2.8 a good autofocus video lens for run and gun? What other good, reasonably fast autofocus zoom lenses could you recommend for the GH3? (want the long end to be under 30mm equiv) Or is autofocus a lost cause?

My main usage for these would be shooting storms. I need one ultra wide for taking in giant swaths of sky, and then a good zoom. The zoom will be used for run and gun, shooting inside a car at people, or outside towards the storm. A lot of situations where you're out towards dusk, so low light capability is really useful.

With the zoom I'm kind of torn. How useful will autofocus be for me? Some of the tests I've watched on vimeo make some of the panasonic micro 4:3 lenses look pretty decent with video autofocus. It's not necessary, but would be nice. Stabilization may be useful, but I'll have a rig most of the time.(even then though, might be nice) With the metabones adapter, though, I could be getting zooms faster than f2.8 with pretty good quality... but no autofocus or stabilization.

Thoughts?

Thanks.

 

[Thomas Smet]

You may not want to hear this but I would honestly suggest the 14-140 Panasonic lens. Yeah it isn't fast but it is about as good as you can get for run and gun shooting when things get a little crazy. The zoom range, weight, ease of use, auto focus and most of all stabilization are pretty huge factors for the kind of shooting you want to do. Since the GH3 handles higher ISOs fairly well I would honestly go for a good overall flexible lens instead of for the few rare moments when you might shoot at the darkest dusk moments. The GH3 will still do fairly well in low light albeit with a bit more grain. You can always add a couple of low light lenses for those rare moments when the 14-140 will not cut it anymore. For 90% of your time however you will be glad to have the versatile 14-140.