Hi all, I am wondering in the 3D optical transfer function as shown below: http://www.purplebark.net/mra/research/votf/otf-sliced-volume.png The m and n axes represent support of lateral spatial frequencies and the s axes axial. If we were talking about a microscope then it has whats called the missing cone of information-lost axial frequencies. But what i don't understand is why there is only a missing dip in the middle, why is it not flat and only has dimensions m and n. The image suggests that the 3D "lobes" represent mid spatial frequencies in the s axis with it dipping to zero at the origin and at the high end frequency cut off. If the height of the OTF lobes does in fact represent axial information, what is this information? If it can't transfer low or high axial frequencies, why can it transfer mid s axes spatial frequencies? Unless i am misinterpreting the 3D OTF. Thanks for the help!