On 9 Jul 2004 at 21:21, Jostein wrote: > I guess my "complaint" with the *istD is that I feel bereft of control over the > degree of anti-aliasing applied. 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... > > I imagine anti-aliasing as a software filter and a softfilter as an optical > filter...
The purpose of the optical filter is to cause a very precisely controlled optical blur which is designed to prevent the occurrence of optical aliasing at the face of the mosaic sensor therefore I can't see why it shouldn't be referred to as an "anti-aliasing filter" As an aside I suspect that the fact that the term "aliasing" is often incorrectly substituted in software package notation for the word "smoothing" may be the source of the confusion. The *ist D seems to employ an optical anti-aliasing filter which has a band- width that was chose to make absolutely sure that no spatial frequencies above the cut off response of the sensor are allows to hit it's surface. This is precisely why it looks softer than the other cameras on the market but it's also the reason that the colour is most pure (especially at small detail) and the moir� effects are the least prevalent. Hence the nice smooth (predictable) transition to 50% gray at the highest optical frequencies when shooting high contrast test targets. Cheers, Rob Studdert HURSTVILLE AUSTRALIA Tel +61-2-9554-4110 UTC(GMT) +10 Hours [EMAIL PROTECTED] http://members.ozemail.com.au/~distudio/publications/ Pentax user since 1986, PDMLer since 1998
