David Mullen ASC
Moderator
4K as measured on a chart would require a single Bayer-filtered sensor of more than 4K, since you generally can only achieve approx. 75% of the pixel resolution of the Bayer sensor in terms of how much resolution can be measured. In terms of file size, you can convert 4K RAW to 4K RGB so the red, green, and blue channels are each 4K in size.
So you'd want a 5K (or 5.5K-ish) sensor if you wanted to get a debayered RGB image that measured out at 4K.
But honestly, 4K is not some magic number, it's just an arbitrary mark, just a goalpost. There isn't really an exactly "true" 4K RGB camera out there to compare with.
However, I'm all for improving the resolution of these digital cameras. More resolution, though it involves processing more data, gives you more detail to work with in post.
So you'd want a 5K (or 5.5K-ish) sensor if you wanted to get a debayered RGB image that measured out at 4K.
But honestly, 4K is not some magic number, it's just an arbitrary mark, just a goalpost. There isn't really an exactly "true" 4K RGB camera out there to compare with.
However, I'm all for improving the resolution of these digital cameras. More resolution, though it involves processing more data, gives you more detail to work with in post.