Diffraction Limited

The resolution of an optical imaging system like a microscope or telescope or camera can be limited by multiple factors like imperfections in the lenses or misalignment. There is however a fundamental maximum to the resolution of any optical system which is due to diffraction. An optical system with the ability to produce images with angular resolution as good as the instrument's theoretical limit is said to be diffraction limited.
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1. In optics, pertaining to a light beam in which the far-field beam divergence is equal to that predicted by diffraction theory. 2. In focusing optics, pertaining to a light beam in which the impulse response or resolution limit is equal to that predicted by diffraction theory. (188 ) [After 2196]