Simulating diffraction limiting in a pinhole camera

Authors: Stephenson, I.

Journal: Imaging Science Journal

Volume: 57

Pages: 162-166

ISSN: 1368-2199

DOI: 10.1179/174313109X442498

Abstract:

Images synthesized by the simulation of light transport are typically generated with the premiss of rays passing through a theoretical or ideal pinhole, the implication being that an infinitely small hole will produce a perfectly sharp image. However, this is not the case. Ray and particle based models of light transport cannot reproduce the effect of diffraction limiting found of small aperture systems.

Here we consider a more appropriate wave based model. While computationally expensive, and practical for only very small apertures, it is capable of reproducing the results of a real pinhole camera. In simulating such a system, we observe that superposition of waves from multiple photons is unlikely to occur in real systems, and that Nyquist theory can be used to explain diffraction limiting as a sampling artefact.

Source: Manual

Preferred by: Ian Stephenson