#Anti-Aliasing Filter

ˈan(t)ē-ˈālēəsiNG-ˈfiltər

Aliasing is an effect that can show up in an image with a very fine edge or fine detail. It is manifested as a smooth edge becoming jagged. Moiré, the most common form of aliasing in digital photography, is manifested as a very fine pattern that becomes highly distorted in both its pattern and color.

Many digital cameras therefore have an anti-aliasing filter, which reduces moire and other aliasing artifacts, although it also causes fine details to be slightly less sharply captured.

Cameras without an AA-filter, as it is called, render extremely fine detail, however they are more vulnerable to aliasing and moire problems.