What exactly does the option “Use max FSC over classes for filtering” do in heterogeneous refinement?
My assumption is that it means that all the classes are lowpass filtered at each iteration to the highest resolution attained by any class at the end of the previous iteration. Is this correct? Are the per-class FSCs still used to limit the resolution used for alignment in the subsequent iteration, or is that also based on the maximum resolution of any of the classes?
And if this option is switched off, does it then filter and align using the per-class FSCs?