5MP is just very small these days. 3840x2880 is practically the minimum you want to go (to be able to capture 4k shots) and that is already 11+MP.
For 4k video there is the additional challenge that if your sensor is not exactly the right size then how are you going to sub-sample it? I bet it is not a complete coincidence that the quoted 48MP figure is pretty close to 4x above 11MP (=double the horizontal/vertical resolution); I imagine they are planning to sample every other pixel over 8K area, which probably brings in all sorts of benefits.
Who watches their photos on a 4K display and pixel-peeps that they're 20% less that its full resolution? (4K is about 8MP -- but you need to go to 2MP (square root of 8MP) to have half the visual resolution. 5-6MP to 8MP is much closer that it looks on paper, as the change is not linear (pixels cover an area, not a line).
That is bit borderline claim. My reading would be that the image would have about 180 PPI (or less..), which is maybe passable but certainly not above human ability to notice improvement to something like 300 PPI. Assuming of course sufficiently good printer etc.
That’s what you get with this in low light conditions: a 12MP image. If enough light is available, you get a 48MP image. Best of both worlds, so to say.
