Ultra zoom approximates a pixel grid, but the pixel grid it approximates no longer exists (and arguably never physically existed, it was always a mapping scheme

Ultra zoom approximates a pixel grid, but the pixel grid it approximates no longer exists (and arguably never physically existed, it was always a mapping scheme). We tend to think of pixels as square bricks, but even in the CRT era they were closer to 4:3 rectangles than squares, and that too was an approximation because phosphor beams were a fairly analog technology and hitting a square (or rectangle) grid was an imperfect thing, especially with something as excitable as light. That's why popular arcade emulators have been picking up CRT filters that bleed neighboring pixels over each other to more accurately rebuild the CRT experience. That's part of what led to dithering being as much or more important than exact color matching. That's also what led to advances at the time in sub-pixel anti-aliasing such as the earliest forms of Microsoft's ClearType brand which blended neighboring colors to make perceptually cleaner font rendering. As we've moved to solid state hardware the grid didn't get more exact, and sub-pixels became even more interesting, rather than less. Most LED displays are triangular shapes, not square grids, with red/green/blue LED diodes packed closely together to map a virtual pixel. (To my understanding some LED displays get even more complex with hexagonal or octagonal packing.) The device-specific grids even more rarely today reflect what we would expect of a "square" pixel grid. (Or even a 4:3 rectangular grid.) Square cartesian grids are easy to program with it. It's always been a useful abstraction, even in the CRT era. It's easy to forget that it was always an abstraction. Ultra zoom operates on the abstraction, not the physical reality. It explodes a cartesian grid, because that's mathematically easy (and the useful abstraction we like to program with). (All of that is before you get to things like OSes and Browsers gave up on mapping the virtual pixel cartesian grids to physical "pixel" grids in real life because the "pixels" became too small, so most users see "16px" fonts as 125-175% expansion to keep fonts readable without magnifying glasses. Web Browsers have "lied" about the physical size of pixels since roughly the end of the CRT era and browser pixels are font-relative too, in which case the other font-relative measurements are often more useful simply for being "honest". Nobody really wants "pixel perfect" accuracy in websites, not even the designers that pride themselves on it and think it matters more than other characteristics like responsive adaptability to device type.)