Simon Young

I'll answer it for you and I've used the A7s3 and FX6 but not the A7IV.
Both cameras have heavily processed shadows that ruin the image. The A7s3 and FX3 are superior because you can shoot RAW externally and bypass the processing. Dynamic range isn't useful when it's being ruined by noise reduction.
The fx30 has much less processing at the lower native ISOs and would be my choice over either of those cameras. Or get a Nikon Z8.

It's downsampled in camera from 5.4k.

Kinsons seems to be a very sympathetic fellow, encouraging proper tests of DR and in this interview he really stresses the dual gain conversion of this sensor - which is frankly amazing. A global shutter with dual gain conversion is unheard of before.
 
 

Apparently it's a global shutter, so I'd imagine the rolling shutter performance to be significantly above average!

5K global shutter, dual gain sensor and "the best dynamic range out of all their cameras". Shipping in October. People are already whining about the price of 3999 dollars ("ITS NOT FULL FRAME"). This is why we can't have nice things and I fear this might sell very badly of course.
https://www.newsshooter.com/2023/09/16/z-cam-e2-m5g-global-shutter-cinema-camera/

5K global shutter, dual gain sensor and "the best dynamic range out of all their cameras". Shipping in October. People are already whining about the price of 3999 dollars ("ITS NOT FULL FRAME"). This is why we can't have nice things and I fear this might sell very badly of course.
https://www.newsshooter.com/2023/09/16/z-cam-e2-m5g-global-shutter-cinema-camera/

LOL, well put!

5K global shutter, dual gain sensor and "the best dynamic range out of all their cameras". Shipping in October. People are already whining about the price of 3999 dollars ("ITS NOT FULL FRAME"). This is why we can't have nice things and I fear this might sell very badly of course.
https://www.newsshooter.com/2023/09/16/z-cam-e2-m5g-global-shutter-cinema-camera/

5K global shutter, dual gain sensor and "the best dynamic range out of all their cameras". Shipping in October. People are already whining about the price of 3999 dollars ("ITS NOT FULL FRAME"). This is why we can't have nice things and I fear this might sell very badly of course.
https://www.newsshooter.com/2023/09/16/z-cam-e2-m5g-global-shutter-cinema-camera/

Is there a chance you could share the original 5K raw files?

The Z8 as an APS-C video camera.
You can shoot RAW in DX mode, which crops the sensor and gives you 5405x3040 clips, better than 5K and much better than 4K. You can shoot RAW at the highest quality (HIGH), with the bitrates 1/4th those for 8K - so you can shoot 48 minutes at HIGH RAW on a 1TB card, as opposed to 12 minutes for 8K!
You can of course us DX (APS-C) lenses in those mode. For this video I used the FF Nikon Z 24-70 f4 lens. An advantage of the crop is that mostly one is using the center of the lens, so corner drop-off is irrelevant - most lenses from Nikon are really good in the center.
So, how does it look:
Think meerkats - habitat and inhabitants in their activities.
5K (5120x2880) frame grabs:
 

Prores HQ looks way better, especially in nlog on the Z8 and the Z9. When you shoot in h265 there's a disgusting amount of internal noise reduction going on no matter what profile you're in and it's not possible to switch it off.

Drum roll please....
I've finally got around to creating and releasing a LUT that gives accurate colour on the S5II and S5IIx. Big thanks to @Andrew Reid for allowing me to post about this.
It's available here:
https://lumasweet.com/shop/p/lumasweetlifelikes5ii

I'll get around to doing a write up on it at some stage. In the meantime, here's a YT video (don't laugh!) that I made about it. This might also be of interest to anyone who's interested in camera colour science in general, even if you don't have this camera.
 
 

The OP of that post claims V-Log and HLG are unaffected. Also, her tests of the normal profiles were in 8 bit, AFAIK.

V-LOG is unaffected. However the smoothing is there even with H265 4:2:2 with every other profiles, exactly like on the GH6. By the way,this is not a news about the GH6.

There's some fuzz in other forums about the S5ii using a new algorithm that seems to smooth skin texture a bit too much. As far as I've seen in the comments this seems to be happening in "normal" picture profiles. Have you noticed a difference in Vlog with regards to this, @hyalinejim? Thank you by the way for the footage and info, really impressed by the s35 quality too, where the rolling shutter seems to be very well controlled.

I can't say that I have noticed a problem with artificially smoothed skin textures in V-Log but I haven't looked very closely so that's not say that it's not there. Deezid often has good insights into detail, noise reduction and sharpening. @deezid there's a link to footage on the previous page if you're interested in taking a look.
If this phenomenon is confined to the normal profiles then that's fine with me as I never use them.
BTW, another issue doing the rounds on FB groups is that in HD 50/60 full frame there is no PDAF, only contrast based. Crop HD is fine, as are normal frame rates in HD. Just something to be aware of.

Ok received the S5ii with 20-60mm and 50mm lens kit this morning, charged the battery had a very quick play and then took it with me on a shoot this afternoon - nothing too taxing or crazy, just filming speakers at a conference and took some photos in between.   
Was able to use it instead of the Canon R6 until it ran out of battery (only had the one, lasted about as long as R6 battery does - couple of hours in 4k). Here are my thoughts so far...
Some real positives over the R6 for this type of work -
No 30 minute limit (one of the talks was 40 minutes) so was nice to capture it all
Able to use my 7" monitor whilst having full access to the cameras touchscreen - this was lovely and so much more relaxing for my ageing eyes. Great to be able to put lut on monitor and also use full HDMI - even without a cage felt more reassuring than horrible micro
No overheating whatsoever in 4k 10 bit 422 for 2 hours - priceless for peace of mind. Once the battery ran out had to use the R6 and overheating warning came on in the last hour so changed recording down to HD for the last speaker
Comparing to the R6 they are very similar in size and weight - S5ii feels very solid, R6  a bit plasticy in comparison although slightly nicer grip in the hand (was marginal though and maybe dependent on hand size).  S5ii AF with the 20-60mm and 50mm 1.8 seemed to stick well once it locked onto a face. Nothing very taxing but did a good job I think - will need to check through all the footage but am pretty confident it worked as well as the R6 under these conditions
Audio - used Sound Devices mix pre-d at line level 96khz 24 bit into the S5ii - seems to capture a clean sound, need to do some testing but think it is a step up from the R6 
The 20-60mm lens is probably the best kit lenses I've used - well made, nicely dampened focus ring and zoom. Love that it's 20mm on the wide as opposed to standard 24mm, don't think I'll need any wider. Bit short on the long end but used it in apsc mode - quality seems a little sharper than the r6's crop mode but am only eyeballing off the screen
The 50mm 1.8 is really nice, completely silent AF, nice size and lovely feel to the large focus ring, also quite pleasing bokeh from first impression, felt like a quality lens - obviously in a different price bracket to the Canon 50mm STM lens but yes a lot nicer to use 
That's all for now, feel like it could be a good purchase though of course early days so time will tell, used vlog and am just trying some luts in Resolve now - looks pretty good for conference type lighting

Looks like there is a variable 10x FHD zoom function…which leads me to believe the FHD 24p image is oversampled. If so that’s huge. 

Cmon. Go to the Vimeo site and download the original - it is 8K. The same 8K video was uploaded to YouTube. I have no control over what YouTube streams.
I do not like being called a liar, particularly when  I went out of my way to post on Vimeo so folks could download the un-recompressed 8K original.
It is people like you that steer away posters.
 
 

I'm sure those lenses are great but the line-up just feels limited compared to RF, which now has lot of third party lenses including cine glass. The RF 35mm f1.8 is also a much cheaper STM lens but a great offering considering it has IS and Macro for under 500. I don't even think Z lenses have IS?

I would get a Z9 mostly because of the incredible S-lens line-up. Beautiful lenses all of them - barely any focus breathing, weather sealed, fast accurate and silent autofocus and beautiful rendering. The Z 35mm f1.8 and Canon RF 35mm f1.8 are miles apart. And the Z 24-70 f2.8 is quite possibly the best 24-70 ever made.

Sad to see Canon play us like this. Sold my R5 a long time ago and lost a chunk of money. 
 
This dude has measured the temperature of the outside of the camera when recording with the new firmware. It seems to stabilize to around 102 degrees Fahrenheit around 60 minutes and then stay there in 4KHQ.
I wonder if the sensor gets noisier with these temperatures sustained. Have you noticed anything Andrew?

Eh? Where did I say it was "burning hot"?
There are two separate discussions going on here. What type of overheating do you still think is the problem? Do you really think to avoid skin burns the camera needs 1 hour cooling off timer set in firmware plus arbitrary timers for 2 years upon release, then quietly removed with no explanation?
First discussion is about what the camera hardware is capable of. The hardware we pay for should be fully usable. Are the operating temps of the CPU and image sensor ok under sustained load. As you see from your GPU or CPU these peak temps are reached within minutes, then stabilise. Is the same with the EOS R5. The temps stabilise and the alloy housing acts as a passive cooler to dissipate the heat to the air.
Second discussion is the external temp in contact with skin and how hot is too hot or against consumer regulations and whether it can cause skin burns. If Canon is trying to avoid this, then why remove the limitation now? Did the rules change? I don't think so somehow.
Then there is the related discussion of Canon segmenting the market and whether they wanted EOS R5 to be used in place of R5C and C70 for pro video production. All three of these were planned at same time with staggered release schedule. What capabilities are fully reliable on which models is a question of firmware not just hardware.
So to answer discussion 1 - We proved way back in 2020 that the EOS R5 hardware was capable of running for long periods even in 8K with the EXIF temps never going above 65c and the battery pull + screw in the battery door trick was possible to reset the 'overheating' timer counting down in firmware.
It was capable of restarting a recording immediately - but remember the old firmware had a lengthy 45 minute to an hour long 'cooling off period' which was clearly bullshit because it didn't even take into account actual temperature sensors in the camera. For example the camera being in a fridge recording 8K where it would cool to room temp within a couple of minutes after stopping. It still had that arbitrary timer blocking you from the features and not allowing the use of the hardware you paid for to the full potential.
I was contacted by a class action lawyer in the US during these discoveries, and the whole thing was talk of the town. Canon were really on the back foot PR wise. All their own fault. They had created the perception of an unreliable but expensive flagship camera, and that their new hardware was overheating.
So rather than recall it and change the firmware, or even just apologise to their users who had spent the money on a defective cripple hammered camera, they enlisted their client journalists to say nice things about it and brought out a faux-fix firmware update that did barely anything.
So that was the situation for EOS R5 owners for 2 years until this complete U-turn last week.
I don't. I have no use whatsoever for "unlimited" recording times.
I just want normal predictable behaviour from a camera especially for £4000.
30 min limit is fine by me, I am not an event shooter.
Remember how severe the problems were with the original EOS R5 firmware - you could be in the menus or just shooting a few stills and an hour later the camera would be locking you out of the high quality 4K mode and 8K.
So by my standards I only have to be able to use the camera normally without being blocked by fake timers.
I kept saying all along after the magic screw trick, it was a firmware restriction, not real overheating. Nobody would listen. Even Magic Lantern were saying it. Nobody listened to them either.
Now the lifting of the firmware timers proves it.
But still people's minds don't change.
All I can say is I can explain it to you, but I can't understand it for you.

@Attila Bakos Dunno, here is the page dedicated to the new sensor: https://fujifilm-x.com/fr-fr/products/x-trans-cmos/
What I wonder is if they have finally found a way to fix those false color issues plaguing Xtrans that we talked about couple months ago? does this point give promise:
Arrangement of G pixel on all diagonal lines
G pixels are placed in all diagonal lines. It improves the accuracy of diagonal high-frequency image detection and color interpolation