= Retinal receptor pitch and angular sampling
{title2=$\theta_{\rm pitch}\simeq1/(f\sqrt n)$}
For a roughly square array of retinal receptors with surface density $n$ and image distance $f$, the pitch is $s\simeq n^{-1/2}$ and its angular scale is $s/f$. Reconstructing a periodic spatial pattern requires at least two samples per period under the <Nyquist–Shannon sampling theorem>. Receptor density alone does not specify lattice geometry, contrast sensitivity or a unique point-source resolution criterion.
Back to article page
