Estimate the aperture at which diffraction begins to limit resolution for a given sensor pixel pitch.
小像素传感器更早遇到衍射极限。
| Item | Formula / Rule | Source / Standard |
|---|---|---|
| Airy disk | d = 2.44 × λ × N, giving d ≈ 1.34 N µm at 550 nm | Airy, Transactions of the Cambridge Philosophical Society, 1835 |
| Pixel criterion | Diffraction stops limiting once pixel pitch p ≥ 1.22 × λ × N | Rayleigh criterion, 1879 |
| Typical threshold | Full-frame 4 µm pixels begin to soften past f/11 and visibly at f/16 | ISO 12231:2012 Photography — Vocabulary |