The Fourier transform of two points is a grating. This is a common optical
transform which can be performed with a laser and two pinholes.
Eight points in an array make a very small crystal lattice. Since the lattice
is very small, the diffraction spots are very large.
Fifteen points in an array make a more realistic crystal lattice. The
reciprocal lattice is clearer now.
A molecule.
Two molecules.
Eight molecules.
Fifteen molecules.
A duck with a missing shell of data:
The edges are sharp, but there is
smearing around them from the missing intermediate resolution terms. The core of
the duck is at the correct level, but the edges are weak.