Why did 405 look so good?

[Hartley118]

David, that was a very instructive experiment........

I think there was also another psycho-optical effect at work, rather like visible scan lines suggesting a sharp picture. The aliased fine detail caused by a shadow grille could make a picture seem sharper than it actually was.

The impression of sharpness arising from aliasing could also account for a puzzling observation on PC screen resolution.

Once upon a time, many of us were limited to a 640x480 VGA screen resolution which, though limited, produced nice crisp graphics and text.  Today, though, with a typical PC monitor resolution of 1920x1080 (HDTV), if I should happen to display a VGA picture on it, it looks to my eyes decidedly soft and fuzzy, much worse than on a native VGA screen.  For text and graphics to look crisp on my HDTV monitor, it requires an  input of HDTV resolution.

So it does appear that the best subjectively sharp image is obtained if the native resolution of the display matches that of the video signal.  A higher resolution display merely softens the subjective effect, making it look unsharp.

Without wishing to drift too far OT, I don't think that there's any analogous effect with audio: widening the frequency response of the reproduction system doesn't cause a limited bandwidth audio signal to lose any subjective crispness.

Martin