BTM_Pix

The Fotodiox WonderPana system will let you mount filters on it.
https://fotodioxpro.com/products/wpcore-tmr1530
If you get the FreeArc Core package you can then put 6.6 square filters in.
Welcome to the world of expensive filters though  

Thanks for the info!
I'm in Madrid.

My experience with the specific Metabones that you are after for M43 cameras is mixed.
The work I'm doing on my hardware focus controller for Panasonic cameras has involved me creating a calibration procedure and the number of focus points for a native M43 lens is on average around 200 depending on the lens. On an EF lens via the Metabones its less than half that. And often much less than half that. This doesn't mean that it doesn't focus necessarily just that its very coarse in its points and the camera is returning some errors from it when trying to drive it too quickly between points. 
Now, all that might not seem to necessarily matter in terms of normal operation because I'm doing something completely different with it but it does tally with what I'm seeing from it when I am using it in normal operation where it is being a bit skittish. And this is using it with a variety of lenses from Canon including some short and long L lenses as well as more lower end ones like the nifty fifty and EF-S lenses but also the Sigma 18-35 1.8. 
Optically its fine, the aperture control is fine and the AF is generally OK but I would definitely advise that you try one out with the specific lenses that you will be using it with and see if it is right for you. Unfortunately, thats tricky depending on where you are as even in London I found nowhere that I could demo one.
 

Maybe you might want to look at the Aputure Lens Regain system as an alternative. It'll give you the lower light and FOV reduction and aperture control of the EF lenses and if you're used to manual focus only anyway then the focus control might be a good halfway house for you. 
Yes its essentially manual but the two programmable hard stops might work well for you for zone focusing as well as being creatively useful for focus pulls. If nothing else it will give you hands off focus control of the Sigma which is no bad thing for a few reasons with that lens.
Its a lot cheaper than the Metabones as well but its a bit bigger because of the wireless interfaces. 
I have both and if I only had to have one then, for me, the AF of the Metabones isn't impressive enough to choose it over the Aputure.

Maybe you might want to look at the Aputure Lens Regain system as an alternative. It'll give you the lower light and FOV reduction and aperture control of the EF lenses and if you're used to manual focus only anyway then the focus control might be a good halfway house for you. 
Yes its essentially manual but the two programmable hard stops might work well for you for zone focusing as well as being creatively useful for focus pulls. If nothing else it will give you hands off focus control of the Sigma which is no bad thing for a few reasons with that lens.
Its a lot cheaper than the Metabones as well but its a bit bigger because of the wireless interfaces. 
I have both and if I only had to have one then, for me, the AF of the Metabones isn't impressive enough to choose it over the Aputure.

I'm pretty sure it's already 16-235 in gx80/85 by default

I think there'd be a pretty big market for it.
For people with LX100 or GX80 you're getting edit ready ProRes and an audio recorder. That takes both of those cameras to another level, particularly the GX80.
For everyone else, the edit ready ProRes would be very attractive even just based on how many threads pop-up on here recently for workflows/computer requirement headaches to handle 4K. Having ProRes from the get go takes care of a lot of that pain. Well, until you have to buy all of those hard drives !
The drop in CFAST prices since the original Ninja Star appeared also means the timing is better for it now as well.
As far as I'm concerned, BM have the right spec with the wrong screen size with their VAs as 4K on 5" would be better for compact cameras and Atomos have the right spec on the Ninja Assassin but the wrong screen size too as maybe it shouldn't have one at all like the Ninja Star.
So for me at least, whichever of them does 4K on a 5" screen or 4K on a no screen will win.

I think there'd be a pretty big market for it.
For people with LX100 or GX80 you're getting edit ready ProRes and an audio recorder. That takes both of those cameras to another level, particularly the GX80.
For everyone else, the edit ready ProRes would be very attractive even just based on how many threads pop-up on here recently for workflows/computer requirement headaches to handle 4K. Having ProRes from the get go takes care of a lot of that pain. Well, until you have to buy all of those hard drives !
The drop in CFAST prices since the original Ninja Star appeared also means the timing is better for it now as well.
As far as I'm concerned, BM have the right spec with the wrong screen size with their VAs as 4K on 5" would be better for compact cameras and Atomos have the right spec on the Ninja Assassin but the wrong screen size too as maybe it shouldn't have one at all like the Ninja Star.
So for me at least, whichever of them does 4K on a 5" screen or 4K on a no screen will win.

I think people would happily pay a little for an hour with all sorts of used test gear to play with in a special room.
It would be much nicer than feeling guilty wasting the shop owner's time and having just 5 minutes with the next customer breathing down their neck.
The larger retailers can usually match Amazon prices, sadly the smaller ones don't seem to be able to, so maybe they are better trading in used goods and rarities instead.
PS ntblowz I had to delete your signature as it messed up the readability of the forum having a big long quote randomly appearing in threads. Sorry about that. Feel free to put something else in there that's smaller.

It wasn't much better there !
I'll be back late November for about a week so I'll give you a shout.

At that price, if you hate it, you'll get your money back on it all day long.
Oddly enough - if as most 1DCs its got sub 20K clicks on it - you could probably make a profit selling it to someone who wants a 1Dx as you won't get any change out of £3K for a similar one of those. And the 1Dx is likely to have had a much tougher life so the 1DC would be a much more attractive proposition.
I have a rapidly expiring Nikon D4 and the at these prices the 1DC is batting its eyelashes at me as exactly that sort of proposition. I have enough short to medium Canon glass to use it for work alongside the Nikon for long stuff and of course I get a massive bonus feature thrown in with the 4K. 
I already get some open mouthed reactions from other photographers when covering games with a combined Nikon and Fuji setup but its nothing compared to doing it with an unholy alliance of Nikon and Canon! I did it a few years ago and people looked genuinely frightened at what might happen
 

At that price, if you hate it, you'll get your money back on it all day long.
Oddly enough - if as most 1DCs its got sub 20K clicks on it - you could probably make a profit selling it to someone who wants a 1Dx as you won't get any change out of £3K for a similar one of those. And the 1Dx is likely to have had a much tougher life so the 1DC would be a much more attractive proposition.
I have a rapidly expiring Nikon D4 and the at these prices the 1DC is batting its eyelashes at me as exactly that sort of proposition. I have enough short to medium Canon glass to use it for work alongside the Nikon for long stuff and of course I get a massive bonus feature thrown in with the 4K. 
I already get some open mouthed reactions from other photographers when covering games with a combined Nikon and Fuji setup but its nothing compared to doing it with an unholy alliance of Nikon and Canon! I did it a few years ago and people looked genuinely frightened at what might happen
 

At that price, if you hate it, you'll get your money back on it all day long.
Oddly enough - if as most 1DCs its got sub 20K clicks on it - you could probably make a profit selling it to someone who wants a 1Dx as you won't get any change out of £3K for a similar one of those. And the 1Dx is likely to have had a much tougher life so the 1DC would be a much more attractive proposition.
I have a rapidly expiring Nikon D4 and the at these prices the 1DC is batting its eyelashes at me as exactly that sort of proposition. I have enough short to medium Canon glass to use it for work alongside the Nikon for long stuff and of course I get a massive bonus feature thrown in with the 4K. 
I already get some open mouthed reactions from other photographers when covering games with a combined Nikon and Fuji setup but its nothing compared to doing it with an unholy alliance of Nikon and Canon! I did it a few years ago and people looked genuinely frightened at what might happen
 

At that price, if you hate it, you'll get your money back on it all day long.
Oddly enough - if as most 1DCs its got sub 20K clicks on it - you could probably make a profit selling it to someone who wants a 1Dx as you won't get any change out of £3K for a similar one of those. And the 1Dx is likely to have had a much tougher life so the 1DC would be a much more attractive proposition.
I have a rapidly expiring Nikon D4 and the at these prices the 1DC is batting its eyelashes at me as exactly that sort of proposition. I have enough short to medium Canon glass to use it for work alongside the Nikon for long stuff and of course I get a massive bonus feature thrown in with the 4K. 
I already get some open mouthed reactions from other photographers when covering games with a combined Nikon and Fuji setup but its nothing compared to doing it with an unholy alliance of Nikon and Canon! I did it a few years ago and people looked genuinely frightened at what might happen
 

At that price, if you hate it, you'll get your money back on it all day long.
Oddly enough - if as most 1DCs its got sub 20K clicks on it - you could probably make a profit selling it to someone who wants a 1Dx as you won't get any change out of £3K for a similar one of those. And the 1Dx is likely to have had a much tougher life so the 1DC would be a much more attractive proposition.
I have a rapidly expiring Nikon D4 and the at these prices the 1DC is batting its eyelashes at me as exactly that sort of proposition. I have enough short to medium Canon glass to use it for work alongside the Nikon for long stuff and of course I get a massive bonus feature thrown in with the 4K. 
I already get some open mouthed reactions from other photographers when covering games with a combined Nikon and Fuji setup but its nothing compared to doing it with an unholy alliance of Nikon and Canon! I did it a few years ago and people looked genuinely frightened at what might happen
 

So in my personal experience...
Just in Berlin two great stores I regularly visited have simply disappeared in the month I was away!
So sad to see Photo-Stade go. He was always a true enthusiast and owned an FS7
In the bigger retailers for the first time the camera sections have been shunted to the back of the floor or in some cases an upper floor instead of ground/first.
Even at Manchester airport I noticed the cameras had been moved to the back.
If Canon and Nikon don't get their finger out soon and start innovating and winning back smartphone users the whole industry is going to suffer, not just the corporate giants (who can move into medical and other profitable sections and survive just fine). It's the whole ecosystem that's at stake.

Read the spec sheet, saw all of the things it doesn't have, saw the price, know full well I have zero lenses for it.....
Still did this
 

Read the spec sheet, saw all of the things it doesn't have, saw the price, know full well I have zero lenses for it.....
Still did this
 

Actually bought a used GX85 because of the capability you gave the camera to shoot in Cine-D. Decided to get it as a B-cam to my GH4 and they match well in post with the GH4's Cine-D.

Thank You, BTM_Pix.

Read the spec sheet, saw all of the things it doesn't have, saw the price, know full well I have zero lenses for it.....
Still did this
 

So, as some of you may know, I've been "experimenting" with having little chats with different Panasonic cameras over WiFi and after whispering in the GX80s ear last night, I may have come up with something quite interesting.
The first image is a grab from a GX80 using its Standard profile.
The second image is a grab from a GX80 that is definitely not using the Standard profile.......

Read the spec sheet, saw all of the things it doesn't have, saw the price, know full well I have zero lenses for it.....
Still did this
 

Read the spec sheet, saw all of the things it doesn't have, saw the price, know full well I have zero lenses for it.....
Still did this
 

Unbelievably, the shop had an actual Panasonic rep in who was eager to help me evaluate the G80 so I had to think on my feet.
"Can I just see how the focus tracking works when its being controlled by the app compared to my GX80?"
"Of course"
"OK, you go over the other side of the shop and I'll put the app on and then you walk towards me. Slowly".
" OK....Is this far enough? "
"No. Further away".
(Faintly) " How about now?"
"Yes. Now walk back really slowly"
(pretend to study app screen while sending commands)
"How did it do?"
"Its the same as the GX80 so I'll stick with that for now"
 
What's also the same on the G80 and the the GX80 is that VLOG doesn't work on it either.
I have an idea about a clue in the GH4 that might shed some light but don't hold your breath.

OK.
This is a Nikon 200-400mm f4 on a Nikon D800 and a Panasonic G7 via a dumb adapter.
Not exactly inspiring content but its too hot to venture out beyond my balcony at the moment !
The top right frame is the D800 at 400mm f4, the bottom left is the G7 at 400mm f4 and for comparison the bottom right is the D800 frame cropped to the same FOV as the G7 is giving.
So the answer in terms of absolute quality I suppose depends on the lens but, comparatively speaking, this should be a good yardstick to show you whats possible. The cropped D800 is still a fraction better but we are comparing two radically different cameras here (let alone price difference) so I wouldn't let that put you off and certainly not in terms of resolution for video.
For what its worth, I have actually experimented with an M43 camera (an Olympus OMD10)on a long lens during a cricket test match. For the uninitiated, a cricket test match lasts for 5 days so leaves plenty of time for experimentation to relieve the long periods of tedium covering it    In actual fact, I had it on the Sigma 300-800 so it was capable of a ludicrous amount of reach and the images were competitive but the lag was too much to deal with but with something like a GH5 I might be tempted to give it a go but it'll be manual focus only for me as my long stuff is Nikon.
Anyway, what I would recommend is to put it on a decent tripod (as opposed to this junk I've just had it on for this quick test) with decent adjustment as it will be completely unbalanced having such a tiny camera hanging off the end.