Re: Bayer aliasing on the 5D

Kennedy McEwen <rkm@xxxxxxxxxxxxxxxxxxxx> writes:

>>I also suspect that AA filters are not too steep, which is why some
>>manufacturers choose to use too weak ones, to get more sharpness.

>Of course they aren't - they are only sinx/x functions as a consequence 
>of the lateral half pixel (assuming the AA filter is manufactured to an 
>accurately controlled thickness) shift.

I believe that's a one-pixel shift, not a half-pixel shift.  One pixel
is half a wavelength at the Nyquist frequency, which is a 180 degree
phase shift, so you get the first zero in the filter response at exactly
the Nyquist frequency, which is what you wanted.

(Actually, I've heard of people using a smaller shift like 0.8 pixel to
increase sharpness of in-band detail at a cost of some increased
aliasing).

	Dave
.

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