Re: [ATM] Blank ratios for different materials.

["Mel Bartels" <mbartels@bbastrodesigns.com>]

> > Why is the 9 point worst than the 6 point?
> > Where would the 9 point be with variable angles and variable forces
> turned
> > on?
> 
> 1)poorer symmetry. This is a bit surprising, but a 9 point cell has a 120
> deg rotational symmetry, the 6 point cell has a 60 deg. Maybe there are
> better explanations - also, PLOP usually assumes re-focusing - if not, the
> difference is less.



I think the symmetry analysis is quite important.  Nils has it exactly
correct: the 6 pt is superior because it has rotational symmetry of 60 deg
(6 symmetry positions about the center of the support that the support can
rotate into and be identical) where as the 9 pt is inferior because its
rotational symmetry is 120 deg (only 3 symmetry positions that it can rotate
into) - twice as bad.

Mel Bartels


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