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R5 AA/OLPF filter type?

Started 1 month ago | Discussions thread
OP Bigger Contributing Member • Posts: 640
Re: R5 AA/OLPF filter type?

Atta-Boy wrote:

Bigger wrote:

I think Canon needs good anti-aliasing of vertical lines to prevent DPAF errors--otherwise the camera could misfocus on aliased false details.

if I may ask a question - why 'd DPAF errors occur when multitude of DPAF sensels participate ( are behind each of the focusing points ) and why 'd CDAF ( I think - and I of course might be very much wrong - it is some equivalent aggregation of a number of sensels participating in the focusing operation ) in cameras w/o AA filters not misfocus on aliased false details ?

Because CDAF is dumb, and DPAF is smart, and sometimes too smart by half. CDAF can misfocus when it finds a local maxima in contrast and stops looking, so my 5DsR is prone to this too, but it's rare. Symmetrical AA filters give more defense against this.

DPAF only focuses on vertical edges, so it only needs AA filtering applied in the horizontal direction. I suspect that Canon found that DPAF benefits from relatively strong AA filtering in the horizontal direction, so they have been applying it to all new bodies, but most seem to have relatively weak AA filtering in the vertical direction. This is exactly opposite of the orientation of the asymmetric AA filter by Nikon, so I assume it is related to DPAF.

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