Reddit mentions of Gonine DMW-DCC12 DMW-AC8 AC Power Adapter DC Coupler Charger Kit Compatible with PANASONIC BLF-19 Battery LUMIX DMC-GH3 DMC-GH4 DMC-GH3K DMC-GH4K DC-GH5 DC-G9 Digital Camera.

The GH5 has no recording limit other than your SD cards. You may save space recording in 1080p (or lower resolution) instead of 4k and maybe picking a compressed format (quality may suffer, you will have to try and see what works for you there). To be sure that the SD cards are formatted correctly, you can format the cards from the camera the first time you use them.

As far as I know it's not possible to charge the battery while it is inside the camera, but you could use an AC adapter instead (like this one) and use your camera for hours, as it would only require you to have it plugged in. That said, the battery in my camera lasts way more than an hour so you may not need any adapter.

> I'm in the US. I can't seem to find where to buy the GH4R. My guess is that it's simply a GH4 with some sort of after-market patch or upgrade?

No, it is a Europe-only model. The US model can record for hours without any patches or upgrades.

> how well does the camera perform in low light?

Not very well.

> If it's bad, what can I do to improve the quality in night scenes (if possible)?

Fast lenses and good lighting.

> I take it that this camera can record whilst powered by AC (wall, not battery)?

Yes, I use an AC adapter and dummy battery like [this one] (https://www.amazon.com/Gonine-DMW-DCC12-PANASONIC-Replacement-DMC-GH3K/dp/B01EI2S6OC//ref=as_li_ss_tl?ie=UTF8&linkCode=ll1&tag=battleforthew-20).

Again, hope this is helpful!

I don't think so, but it depends on how often you intend to take photos. The link I sent you, I took a photo every thirty seconds for an hour. Battery life can be extended greatly by using the economy mode that turns the camera off after two seconds, I think it will turn back on for your next timed picture, but you'll have to test it. You'll have to use an external battery solution like this if the battery won't last for your entire time lapse.

2 cams is a must. Forget an fs7, that's overkill and it's going to eat your budget-- I would rent a gh5. It will match your g80 very well (use cine-d) and it has dual card slots.

Shoot 4k on both cameras, and occasionally punch in on them in post to effectively have 4+ POVs in 1080p.

Also, sound is going to be your biggest issue. Ideally, you can plug in a field recorder into the soundboard and get as clean a signal as possible, from the source.

If I were in your shoes, I would rent/buy:

gh5 (rental)-- $50-$100

Tascam dr-o5/Zoom h1 recorder (rental) -- $15-$30

Male/male 3.5mm jack (buy) -- $10

x4 128gb SD (buy) -- $200

x1 64gb micro-sd (for the audio, doesn't need to be fancy) -- $20-$30

x2 Panasonic Dummy batteries (buy) -- $50

x2 Tripods (borrow?)

X1 Lumix 42.5mm f1.7 (rental) -- $30-$50

With those things, you can make it work well.