That wouldn't surprise me. If we couldn't tell them apart. There must also be limits to perception or resolution. Are our eyes even able to tell the difference

That wouldn't surprise me. If we couldn't tell them apart. There must also be limits to perception or resolution. Are our eyes even able to tell the difference between FHD, 2K and 4K on a 15" screen? I tested FHD vs 4K on a 31" screen and could not are a difference when watching a 10 minute video (I had 2 screens side by side for reference). On a semi related note. I also tried watching 60fps videos at 60Hz vs 144Hz (again side by side) to test out my new screen. No difference. Even fast moving things. I really feel like either I just don't perceive these things and it'll keep more money in my wallet, or that I'm not alone and everybody can save money. A chart of when differences actually become perceptible would be great. It wouldn't surprise me I'd the threshold for 4K were 42", 10bit only in grays and fps at a certain pixel per second movement speed.