Originally Posted by Mad Lust Envy
In scientific testing (let's call it scientific), A perfect diagonal line of one pixel width moving at the rate of one pixel jump vertically and horizontally will look perfectly straight at around 9 feet from a 60-inch screen for ME. It will no longer look like pixel stair stepping after that. The point where the line doesn't look like stairs is the limits of YOUR eyes at that specific resolution since one pixel difference will look like a straight line. So beyond that distance,. I wouldn't gain absolutely any benefit over 1080p.
You keep bringing computer games, no AA, but that is not a normal occurence, and again, is limited to specific individuals.
We're talking normal content, which will undoubtedly have post processing done.
But once you get your 4K TV, enjoy justifying it as much as you want. The rare cases where it will matter are so few and far between, especially for the vast majority of consumers.
It's 320kbps vs lossless all over again.
Your example explains a photograph, not a video. So let's finish your experiment.
Once you get to the distance where that single pixel length line looks solid, let's rotate it slowly to horizontal. In doing so (without AA), there were be parts of the line that disappear, because the math says the width is less then half a pixel. There will also be parts of the line that's two pixels long, next to a single pixel length. You will be able to tell it's not a solid line as it rotates.
Now let's make it even worse. Le's say it was not one line, but 10 single pixel lines one pixel apart. When you get to the point where all you see is 10 diagonal lines, and no pixels, when you rotate them all to horizontal, you will start to see a moire pattern, as each line at some points is two pixels apart, and at other points touch each other. Once they get to horizontal, they will look perfect again.
We fix this today with anti aliasing. The problem is for the last experiment, if you turned on AA, you would not longer be able to pick out those 10 distinct lines. When you rotated them they would not look out of place, but you will look like your rotating a strange pattern, and not 10 lines.
Now stay in the exact same place without AA turned on, replace your 1080p TV with the same size 4K TV, and do the exact same test at 4K, and the image as the lines move to horizontal will look vastly improved.
Edited by JeremyR - 12/23/13 at 12:35pm