masked reflector resolving power?

On the discussion of masked scopes with multiple holes in the mask to get rid of spider spikes...

Does the multiple hole mask give you the resolving power of the full width of the mirror? For example - do two 4" holes on opposite sides of a 10" mirror give you the resolving power of a 10" scope or is it that of a 4" scope, or something in between? I can almost convince myself either way...

And if theory says one thing, does practice say the same?

Thanks,
Charlie

The only mask that comes close to the resolving power of the full aperture is hexagonal, around a 33% c.obstruction.
It is still inferior, due to roughly a magnitude brighter 1st ring. The fewer holes, the more inferior resolving limit
of a mask vs. full aperture. A two-hole mask (holes at the diameter) would have a sort of elongated central spot, with the length equal to that of the central spot of a single opening, and the width about 1/3 of it (depends on the holes' relative separation). The "empty" space of this shape (if you imagine it encircled) conatins a couple of very bright spikes. The resolution in one direction is similar to that of a single opening (slightly better, due to less energy outside the central spot), and somewhat better in another one, but not by much, due to those couple of bright spikes that get in the way.

Practice will inevitably differ from what the theory says, because there is a number of variables that affect the final result, which in a typical (read: uncontrolled) practical environment are partially or entirely ignored.