ac6000cw

I've noticed that too - I bought my G9 about 18 months ago in the UK (new but cheaper than used at the time, due to very generous cashback offer and v.good price from dealer), and used prices have been steady or slowly edging up since then. I suspect due to new camera sales being well down (so fewer trade-ins/private 'upgrade' selling) there is just less used product around to buy which is pushing prices up. It's noticeable that some of the big dealers in the UK have been actively advertising to buy used equipment during the summer, including some selective cash buying offers where normally they would only take trade-ins. I suspect that used prices on the G9 will only drop substantially when it gets replaced by a new model, but I don't see any sign of that happening any time soon (and it's already a very feature-packed, high performance 'hybrid' m43 camera anyway).

I'd agree - if you want to stay with m43, the G9 is the way to go, it's a great hybrid stills/video camera with superb quality 1080p and no-sensor-crop 4k up to 60p, plus outstanding IBIS/EIS.

That's very low bitrate for 4k (only about 10 Mbit/s) - 4k25p files from the camera are about 100 Mbit/s for the EM10 and G80, so 22 minutes would be about 16 GB.

Correct. If you are in 'creative video' mode (the 'movie camera' icon on the mode dial) the LCD/EVF screen will show you the correct 'field of view' (FOV) for the movie setting in use (1080p or 4k) all the time. If it's in any other mode it will normally show the 'photo' FOV, then change to the correct 'video' FOV when you hit the video record button.

I agree with Kye that top-quality 1080p (e.g. GH5/G9 level) isn't very far below 4k quality, particularly if your final output is heading for YouTube etc., and it is a lot faster to work with 1080p when editing. But the quality difference is more noticeable with a lot of cameras due to lower-quality down-sampling/scaling from the full sensor area to 1080p. The GH5 & G9 have the processing capability to do it properly.

Yes, absolutely - I've been using them for a while, at up to 4k60p (150Mbps) in a Panasonic G9 (and other Panasonic and Olympus cameras). I normally use SanDisk 'Extreme Plus' V30-rated micro-SD cards, but you can sometimes get the faster 'Extreme Pro' version for not much more money. I shoot a mixture of 1080p and 4k. Using 4k allows for re-framing in post while retaining enough quality for good 1080p output. I'd also seriously consider a used Panasonic G80/G85 if you are thinking about a used EM-10 III - below the 'GH' level cameras, it's probably one of the best all-round cameras Panasonic have produced. Only real downsides are the crop in 4k and noisy audio from the internal microphones (but it has a mic socket so that's easily solved).

...also the G9 is not compatible with the DMW-XLR1 XLR adaptor unit.

The G9 has no 'All-I' compression modes (in fact nothing above 150 Mbps) but it did gain various 10-bit and 4:2:2 modes in the 2.0 firmware update. It might be that the GH5 IBIS sensor movement isn't accurate/repeatable enough to do a good 'high res photo' mode - or it's just market segmentation. If you look closely at the recent firmware updates for the GH5, GH5s and G9, a few changes have been only for the GH5s and G9 (the two more recent cameras) so I assume they have different (probably faster/more powerful) processing electronics than the GH5. As I don't own a GH5 I can't compare it against the G9, but I don't think you would be disappointed with the G9 - it's in a different league to the G85, GX85 and earlier cameras....

The EM-1 II has a 20MP sensor, no-crop (full sensor width) 4k video, plus phase-detect autofocus, weather sealing, mic and headphone jacks, bigger battery, better IBIS etc. etc. (it's a professional-level stills camera with very decent video and excellent build quality, basically). But it's bigger, heavier and somewhat more expensive than the E-M10 III (in the UK at the moment a used EM-1 II is about twice the price of a new E-M10 III) I seriously thought about buying a new E-M10 III a few months ago, but decided to spend the extra money and get a used EM-1 II instead as I wanted the extra features/weather sealing/build quality.

It's 8-bit

What's the problem with H.265/HEVC licensing - it's handled by MPEG-LA in the same way as MPEG-2 & H.264 as far as I know (and it's quite cheap - free up to 100,000 units per year, $0.20 per unit over that - see https://www.mpegla.com/wp-content/uploads/HEVCweb.pdf )

Minimising the cost of media storage and distribution (bandwidth cost) is what has always driven the development of data compression. It is the reason that broadcast TV originally used interlaced image scanning (it halves the transmission bandwidth compared to using 'progressive' frames at the same picture update rate).

What is your budget? You seem to be looking for the perfect camera but that doesn't exist, so you have to compromise to get as many of the features you would like and put up with things you don't like (especially if the budget is fairly limited and you want it small and light). I'd prefer the G9 to be smaller and lighter, but I put up with that to get the features I want (like excellent IBIS and 4k50p) because they are important to me. If I want to take out a smaller, lighter camera I'll take my GX80 instead and put up with 4k25p, worse autofocus, worse IBIS and shorter battery life in exchange. It's choices and compromises...like life generally...

LX100 isn't a M4/3 camera - it has a 16MP M4/3 sensor, but it doesn't use the whole area (it uses slightly different parts of it depending on the aspect ratio you select). That's why it's a maximum of 12.7MP stills. The lens needs to cover a smaller sensor area, so can be more compact. I think it relies very heavily on electronic correction of the lens distortions, as a trade-off for the small size - even so there is some barrel distortion visible at the wide end, and it's prone to flare sometimes.

I own both of those. LX100 is a great stills camera, and the on-board audio is much better than the GX80. Stabliisation is 'OK' but nowhere near as good as the GX80. Lens is great, although avoid zooming it during video shooting - it tends to look a bit jerky and 'flickery'. No tilting or touch screen, no in-camera charging. The GX80 is a better video camera - better stabilisation, better 1080p, easier to use as a hybrid i.e. switch instantly between stills and video. Tilting touch screen. Has in-camera charging. Poor sounding on-board audio (and there is no mic socket). Viewfinders are about the same on both. Batteries are the same type on both, and battery life (shooting video) isn't brilliant on either, but decent third-party batteries are cheap (as are USB chargers for them) so just carry a few spare batteries with you. I'd go for the GX80 with the 12-32mm pancake, and add the cheap/light/small 25mm F1.7 prime for low light etc. If you want a 'travel zoom' then get the 14-140mm F3.5-5.6 - it makes a nice 'super-zoom' combo while still being pretty small overall. All of those lenses are cheap used, and the two zooms support dual-IS.

I agree completely - it's hard to believe the G100 has been 'designed' by the same product planning team that bought us a succession of ever improving G, GH and GX series cameras - have all the good people departed, or are they being over-ruled by higher-up management? It just looks like a hurriedly-put-together response to the ZV-1 (Panasonic having got wind of what Sony was planning).

Not substantially but noticeably heavier and larger. The EM-1 II is about the same size as a G80/G85 (but heavier). The G9 is taller and deeper but good ergonomically, especially as it has a lot of assignable buttons - the two on the front between lens and grip (under your fingertips) are *really* useful, I have one of them mapped as an alternative video record button.

Only a few of the pro-level native micro-4/3 lenses are heavier (the G9 weighs 658g) and I don't own any of those, partly for that reason - adapted lenses don't count 😉 Even my F-mount Tamron 17-50 F2.8 plus cheap speedbooster combo is less than 600g 🙂

It's a great choice - after 'sitting on the fence' for ages about buying a G9 due to the extra size and weight, I bought one about a year ago and discovered just how good a camera it is - no regrets at all. It's head-and-shoulders better than the G80 I also have - superb IBIS and EIS, no-crop 4k and excellent 1080p, plus lightning fast AF-S for stills (and for my purposes video C-AF works fine, it's much better than people seem to want to give it credit for). I've also recently bought (at the sort of price Andrew mentioned) a used EM-1 II as a smaller but still high-end camera - my first Olympus camera. Not been able to do much proper testing due to Covid-19 lockdown, but it's been interesting so far comparing the two...

Speaking as an experienced FPGA design engineer, if you can implement it in an FPGA you could put into an ASIC (or into software, depending on how fast you need your processing to run). There is nothing magic or special about FPGAs other than their basic ability to be user programmed/re-programmed, which is their 'Unique Selling Point'. That makes them very attractive for low to medium volume products which need high-throughput data processing - instead of sinking a lot of up-front development capital into an ASIC. It also makes it a lot easier and cheaper to fix bugs and add features after you've launched the product.....

The S1H firmware 2.0 update is now available from the Panasonic download page - https://av.jpn.support.panasonic.com/support/global/cs/dsc/download/index4.html (without the "RAW Video Data output over HDMI" function "due to some technical issues yet to be resolved")

Panasonic G9 (with a 10 minute clip limit)

I'd fully agree with that - it also means you can crop/zoom/re-frame/software stabilise with little quality loss (for 1080p output). Incidentally - if you need to convert 4k at 24p/25p/30p to double frame rate, the 'SVPcode' capabilty of SVP (SmoothVideo Project) is worth a look - I used it recently to up-convert 4Kp25 from the G80 to 4Kp50 to intercut with 4Kp50 from my G9 (final edit was 1080p50). It only costs $25 (for a 2 computer license) and as it uses FFmpeg for encoding, in theory you can output the converted footage in any of the encoding formats FFmpeg supports e.g. ProRes. If you intend to up-convert the footage, i think it's better to shoot it with a shutter speed matching the up-converted frame rate e.g. use 1/100s for 25p - that will look better and also provides sharper frames for the software to work with when it does the motion interpolation.

At that price, if it's in decent condition, just buy it... Then add a few cheap 3rd part batteries, V30 rated SDXC cards (for 4K) and some cheap but good lenses and go out and have fun! (I own a G80, G9 and GX80 - the G9 will beat the other two hands-down for video quality but the G80 is smaller and lighter, and the GX80 is the one I usually pick up if I want to take a camera with me 'just in case'. Which one is my favorite - hard to say, it depends on the situation...)

Based on a quick look at dealer prices for *used* G6, G7 and GX80 in the UK, the G6 is maybe £120-160 (but there are not than many listed), the G7 around £250 and the GX80 around £200. On that basis, unless you can find a really good deal on a G6 or you need a mic input, I'd go for a used GX80.