Anti-aliasing filter

A practical anti-aliasing filter will typically permit some aliasing to occur or attenuate or otherwise distort some in-band frequencies close to the Nyquist limit.

[3][4][5] Alternative implementations include the Pentax K-3's anti-aliasing filter, which applies small vibrations to the sensor element.[6][promotion?]

In the latter case, the filter prevents imaging, the reverse process of aliasing where in-band frequencies are mirrored out of band.

Furthermore, because some noise is averaged out, the higher sampling rate can moderately improve signal-to-noise ratio.

A signal may be intentionally sampled at a higher rate to reduce the requirements and distortion of the anti-alias filter.

The narrow 2.05 kHz transition band requires a compromise between filter complexity and performance.