Low-pass filter tech. question?

Canon has implemented a filter cancellation process rather than removal of the Low-pass filter.

Can't help but wonder, that being the case, if/why a User Selectable option would be possible/practical?

Leigh wrote in post #18098175
Canon has implemented a filter cancellation process rather than removal of the Low-pass filter.

Can't help but wonder, that being the case, if/why a User Selectable option would be possible/practical?

These filters are optical pieces. They can't be changed by software. A totally different technology would be necessary to give a choice.

The cancellation is performed by a specially designed piece of optical glass placed over the existing LPF. It's not something that can be removed easily by the user, and certainly not something that can be activated by a menu option.

As for why they chose to put the cancellation optics in rather than remove the existing LPF, I'm sure it involves the optical characteristics of the entire assembly; for example, the sensor including the overlaid filters is intended to have a certain optical thickness in order to ensure that the lens illuminates the sensor appropriately. Roger at LensRentals discovered that if a camera does not have the appropriate type of filter assembly in place, it can affect the apparent characteristics of the lens noticeably. Removing optics without a redesign of the assembly can lead to inconsistent or unhappy results.

GregDunn wrote in post #18098193
The cancellation is performed by a specially designed piece of optical glass placed over the existing LPF. It's not something that can be removed easily by the user, and certainly not something that can be activated by a menu option.

As for why they chose to put the cancellation optics in rather than remove the existing LPF, I'm sure it involves the optical characteristics of the entire assembly; for example, the sensor including the overlaid filters is intended to have a certain optical thickness in order to ensure that the lens illuminates the sensor appropriately. Roger at LensRentals discovered that if a camera does not have the appropriate type of filter assembly in place, it can affect the apparent characteristics of the lens noticeably. Removing optics without a redesign of the assembly can lead to inconsistent or unhappy results.

It might have some color filtration characteristic, too, and if that is the case, omitting it would mean small differences in color conversion, and QE. I would imagine that the cancellation is not complete, too, and a very small amount of filtering occurs, anyway. Does a normal AA filter make 4 true dots from a single dot of light, or does it make 4 tiny disks? The cancellation may create a tiny disk from a point, preventing the most egregious types of aliasing which occurs with dead space between photosites, but still maintaining fairly high potential neighbor pixel contrast.

All speculation, of course.

GregDunn wrote in post #18098193
The cancellation is performed by a specially designed piece of optical glass placed over the existing LPF. It's not something that can be removed easily by the user, and certainly not something that can be activated by a menu option.

As for why they chose to put the cancellation optics in rather than remove the existing LPF, I'm sure it involves the optical characteristics of the entire assembly; for example, the sensor including the overlaid filters is intended to have a certain optical thickness in order to ensure that the lens illuminates the sensor appropriately. Roger at LensRentals discovered that if a camera does not have the appropriate type of filter assembly in place, it can affect the apparent characteristics of the lens noticeably. Removing optics without a redesign of the assembly can lead to inconsistent or unhappy results.

If removed you lose the dust removal as well.