> Application of a elliptical resolution boundary is justified because the
> resolution boundary from common integration programs (Denzo and Mosflm for
> example) is spherical where diffraction for anisotropic data is ellipsoidal.
> A spherical boundary would result in the inclusion of numerous poorly
> measured reflections in the higher resolution shells which effectively makes
> these data more noisy. Imposing an ellipsoidal resolution boundary is
> equivalent to removing noise from the higher resolution bins and is simply
> the anisotropic equivalent of the normal resolution limit truncation.

Hi Justin,

Please be careful in interpreting maps from elliptically truncated
maps, there is a potential for introducing some bias. In Refmac (as
well and Phenix) maps are produced that fill in missing amplitudes
with DFcalc. When your mtz file contains only a small fraction of
miller indices in the highest (spherical) shell, all the missing
reflections will be assigned DFcalc. Depending on your anisotropy,
this can be a significant number of reflections.

I'm not sure how serious this issue is, but it might be worthwhile
checking the 'unfilled' maps as well (both phenix.refine and Refmac
allow you to compute these).



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