[ccp4bb] Resolution and distance accuracies

[Nicholas keep]

We clearly have confidence in distance measurements in crystal 
structures of an order of magnitude better than the resolution ie 
0.1-0.3 Angstroms, but can anyone point me to a more exact theory of 
distance accuracy compared to optical resolution, preferably one that 
would apply to microscopy as well.
Have a Happy Christmas and see many of you at CCP4
Nick