Keeping a subject in focus can become very tricky. An M43 camera set to iso f2 will be much more forgiving and less critical than a FF camera at f2.
Sure enough. Apart from comparing apples and oranges once more, there's nothing to note about this. Where you lost me is with this sentence:
"as it goes I think FF is sucky for video... demanding to manually focus"
To me, the implication here is that FF has trouble performing AF in video, requiring you to do it manually. Since no such statement is made about M43, you further seemed to imply the M43 has an inherent advantage when it comes to autofocus performance.
Now, I am either misinterpreting you here (hence the post asking for clarification) or I am not aware of the most recent comparisons. As far as I know, tracking and eye AF performance from the Sony FF models and now even Canon's with the R6 and R5 is considered superior to at least Panasonic's.
I any case, I would appreciate if you could point me to a comparison that backs up your claim, or elaborate on what you meant.
The larger the sensor the longer the electronic scan takes to pass over the chip, hence greater rolling shutter.
I am not doubting you, but I struggle to find a good source for this. Especially when looking at actual numbers (the theoretical aspects are apparently not appreciated as much around this thread), there aren't as many M43 models as APS-C and FF, but the few that are there do not look like they are clearly superior to either.
If you are correct, what should I expect the advantage of a M43 to be in terms of sensor read speed? Intuitively, I had looked for a difference in time proportional to the sensor area, so 1/4 the time vs FF. That I am not seeing clearly in the numbers presented. There are a lot of different factors at play here (bit depth, what percentage of the sensor is actually samples, resolution of the sensor itself). But if just being 1/4 the size would result in 1/4 the read out speed (=> rolling shutter), I would have expected this to show more clearly.
Numbers I found:
So, in the D5200 thread here, we're kind of worried that this exceptional little toy may have more rolling shutter issues than other cameras. This should be a measurable thing: if we knew how many ms it takes each camera to read the sensor, we wouldn't have to be looking at all those piles of...
www.dvxuser.com
https://www.photohaustv.de/rolling-shutter-effekt-im-vergleich (German)
Again, I would appreciate if you could share your source of you have it at hand, or point me in the right direction.