"Jostein" <[EMAIL PROTECTED]> wrote: >I couldn't agree more on your comments about Photoshop, and I'd like to add >one more reason; the filter inside the camera is nowhere near as good as the >ones in Photoshop. :-)
That's really the point I was trying to make. Guess I didn't do it well enough! >I guess my "complaint" with the *istD is that I feel bereft of control over >the degree of anti-aliasing applied. Well no one gives you that control. >Btw, I'm not entirely sure if it's correct to call it an anti-aliasing >filter when it's implemented in front of the CCD... The *only* time it's correct to call it an anti-aliasing filter is when it's in front of the sensor. Anti-aliasing is by definition the removal of frequencies above Nyquist prior to sampling. Sampling takes place at the sensor itself so anti-alias filtering has to be done before the light hits the sensor. Allowing frequencies above the Nyquist cutoff frequency to reach any sampling system will cause inaccuracies in the final output. I won't even try to explain how this works (it's especially difficult without drawing graphs) but it's fundamental to the process of sampling. I'm sure Pentax doesn't make their own anti-aliasing filter (they're reputed to cost almost as much as the sensor, actually) - I expect they buy the same one Nikon uses for the sensor in the D100. -- Mark Roberts Photography and writing www.robertstech.com
