This line caught my eye....
“That’s not to say that 8K video doesn’t have its uses. Where 8K is useful for filmmakers is the ability to crop the frame. If I edit an 8K video file in a 4K timeline, I’m only looking at 50% of the total image size. This means I can zoom in by up to another 50% without losing any resolution. This gives me a tighter shot and also gives me a cut (a second camera, if you will) within the edit, which, at times, can be a lifesaver. This was the typical workflow when 4K arrived. Initially, people continued to deliver in 1080p, using the full 4K resolution to give them options within the edit,’ he added.
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The same filmmaker discusses how 8k filming is problematic as it means very limited recording times on cards, and really needs a well-specced Mac Pro to cope, not a standard iMac/Macbook.
So, convergence, but only for that middle ground of prosumer as opposed to the mass consumer market that 4K capabilities on the likes of the iPhone have transformed.
QUOTE SOURCE: https://www.techradar.com/news/why-the-canon-eos-r5-could-be-mind-blowing-for-video-according-to-a-director