RandThompson
Possibly. I don’t like to make definitive statements on anything I haven’t tested directly (hence the caveat).
The stress-testing I’ve done, involved long hair swishing across the frame, leaves blowing in the wind and really intricately detailed fabrics being waved around. So lots of really fine detail filling the entirety of the frame. There was no difference between the two formats on any of those tests.
Possibly if you were REALLY digging down deep into the noise floor to recover shadow detail, and de-noising and rebuilding contrast curves specifically for those shadows (in the grade), maybe there will be situations there where you’ll get an edge from the additional bitrate.
But I did test recovering shadow detail with the two formats, and again there was no discernible difference between the two.
That certainly doesn’t mean there won’t be situations where there is a difference. But you really are going to have to push the codec to its absolute limits to see any benefits from the additional bitrate.
Because that is the only difference between the two - XQ has a bit more headroom (data-wise) to capture fine detail, but that’s all it can add. It won’t change the noise-floor of the image in any way, it won’t change the signal-to-noise ratio, it won’t increase your bit-depth or colour resolution, it won’t give you any additional dynamic range. It’s just more bits that can be assigned to really detailed sections of the frame being encoded. That’s all.