paulraphael
Member
I'm not sure what aspects are new. It looks to me like the standard design that's been used for a long time. See the description of opticl low pass filters here.Yes, it's a new design -- and clever.
I agree that it seems to be particularly well implemented. Although part of what makes this easy is simply the high resolution of the camera. More linear resolution means you need less blur. It also means that the unwanted (visible) effects of the filter will effect frequencies where there's rarely much useful optical information from the lens.
The basic strugle with anti aliassing filters, whether in optics or in audio, is that perfect analog filters are impossible to design. A perfect one would be a brick-wall filter ... one that blocks everything above the chosen frequency, and lets everything below that frequency through, completely unimpared.
Since no one knows how to make such a thing, engineers compromise. The effect of a real filter corresponds to a curve, not a wall. The nyquist limit is placed somewhere in the middle of that curve. This means that detail a little above that limit, if the contrast is high enough, can still cause visible aliasing. And detail a little below that limit will be blurred. The game the enginners play is to design as steep a curve as possible, and then carefully balance the strength and center frequency of the filter to give the best performance over the reange of likely uses.
Still we see a subtle difference between the filtered and filterless cameras. If we could have a perfect filter there would be none.