No Anti-Alias filter in Nikon Digital Body?
As a 14-year nikon user I feel I should challenge Nikon consciously.
As stated in Sampling Theory, if sampling rate is not high enough to sample a high frequency signal, a anti-alias filter would be needed to make a proper digital sampling. If not, there would be alias in the sampling result.
Anti-alias filter is basically a low-pass filter that filters out high-frequency portion of the input signal and lets only signals below some certain frequency pass, thus making it possible to sample a unlimited-frequency analog signal with a limited-frequency digitizer. For example to make a music CD, whose sampling rate is 44.1k Hz, we have to first filter out singnals higher than 22.05k Hz and than sample the analog signal with the frequency 44.1k Hz.
The C brand has already been in the music industry for quite a long time so they know to put a anti-alias filter in their upcoming digital camera body. But how about our trusty Nikon? Is there anything designed to take care of the alias problem? If not, is there any reason why Nikon choose not to do some anti-aliasing before digitizing? Or Nikon simply forgets there's a aliasing issue for digital equipment?
#1. "RE: No Anti-Alias filter in Nikon Digital Body?" | In response to Reply # 0AlanC Basic MemberMon 01-Apr-02 06:35 PM
Nikon do use an optical anti-aliasing filter in their digital cameras: the D1 series have a lithium niobate low pass filter bonded to the front of the CCD assembly. I would assume the forthcoming D100 will use something similar.