Dynamic range in video

from what we all learned when we first met the photography world, a bigger sensor = wider dynamic range. 
but as its seem in real world it isn’t the case,

and I don’t talking about pictures now because I don’t know, but in video the dynamic range of the full-frame  a7siii the aps-c xh2s and the 4/3 gh6 are more or less the same.

what do we missing? Does the difference in sensor size doesn’t exist (for DR) because of a weaker link in the chain (like a processor or something ) ?

Just like stills final range is a function of the output device. IIRC Rec 709 is pretty tight at six stops?

That means if you aren't recording at least log you're in a pretty tight place to begin with.  Log can get you twice that. So can RAW.

The other issue is things are often related to the generation of each sensor. That means the best small sensor today might be better than the best large sensor of ten years ago. In spite of the size advantage.

Samuel Dilworth wrote:

sludge21017 wrote:

It appears you would need to record externally to bypass internal NR.

Good point and supporting evidence by video. (I presume it works the same way with the α7S III.)

The FX6 (but not, from memory, the FX3) allows you to record internally without this heavy noise reduction.

Of course the noise reduction is usually useful, not least because it massively reduces the random motion of the image that needs to be compressed by the codec. So it greatly improves overall image quality with the highly lossy codecs we typically use with these cameras.

The codec stress of random noise is less with intra-frame codecs, right? These are available for the fx3 and fx30. And noise reduction smears detail in an ugly way so nr effects on image quality does not obviously increase iq.

Israel Bracha wrote:

from what we all learned when we first met the photography world, a bigger sensor = wider dynamic range.
but as its seem in real world it isn’t the case,

and I don’t talking about pictures now because I don’t know, but in video the dynamic range of the full-frame a7siii the aps-c xh2s and the 4/3 gh6 are more or less the same.

what do we missing? Does the difference in sensor size doesn’t exist (for DR) because of a weaker link in the chain (like a processor or something ) ?

What you’re missing is accepting a gross generalisation as being true in all circumstances.

Many factors affect the DR of the sensor, even before it’s gets to post capture processing (which is what most people talk about here)

All things being equal, a larger sensor could afford a smidge more DR, typically because you tend to be oversampling the noise, so the perception is that it has more DR. I qualified this on a million ways that mean you can never compare apples to apples.

Some cameras are also sensor optimised for DR and some for stills.  You can’t take the stills as the same DR number either.

JB