[account42]

There is also a tradeoff between sharpness and aliasing, that's a bigger driver for microlenses than just capturing more photons. A point sample is only ideal if your sample resolution is above the nyquist frequency which for the real world it won't be.

[formerly_proven]

Yes, this was nicely highlighted by the GFX50 vs. GFX100. Both are around 50% fill factor and have no OLPF, the GFX50 produces a lot of aliasing artifacts, the GFX100 much less so, because Nyquist moves up some 40%, so diffraction takes more readily care of attenuating these higher spatial frequencies.