Dear Marin,
quoting from the 1997 paper:
"The crossing point between the two curves here lies at about 78% of the Nyquist frequency. The theoretical limit for all processing lies at the Nyquist frequency; yet, considerably before that limit, practical limitations due to the 2D or 3D interpolation procedures used limit, or at least interfere with, the information transfer through the processing chain. Moreover, since both 3D maps are processed by the same programs, with the same interpolation routines, the same systematic round-off errors may be introduced in both reconstructions, which the FSC program may see as common “information”. It is thus good practice not to interpret resolution curves at this high end of the resolution range. The sampling of the data at a sampling interval of 5 Å, in our experience, effectively limits the attainable resolution to ∼15 Å rather than to the theoretical Nyquist limit of 10 Å."
You seem to agree that getting close to Nyquist is possible if sloppy real-space interpolation is avoided. As the latter has been the case for at least the past decade, perhaps it is time to let go of an arbitrary rule derived from personal experience rather than signal processing fundamentals?
Cheers,
Dimitry
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