Spell Sunder question

[D'arandriel]

How exactly would spell sunder work against a personal spell like mage armor or shield? Is the DC based on the creature's CMD or caster level?

[fictionfan]

It's against the creatures CMD +5.

[Seraphimpunk]

what if the effect is invisibility ? there's no miss chance for targetting them in the square to hit the invisibility effect, but the target is CMD +5 ?