Call to the lab rats
I have been lurking on this forum since a while and playing Ars since... well, since 2nd edition (ho boys, my bones are creaking, 'm feeling old). This is my first question.
I have a Imaginem specialist who is trying to develop a few improved invisibility spells to travel unseen. He cheerish very much is quiet life and is extra careful (probably too much) to protect his privacy. Also, he is not very practical or pragmatic so his spells are not always optimised.
It has been established in this topic (The Invisible ship) that spell granting invisibility to a structure, grants by default invisibility to its contents, creatures included. However, it is not specified that people which are turned invisible can see each other or, for that matter, anything within the structure. So short of any supernatural ability or adequate spells, they cannot really interact efficiently with the structure or its content (behaving somehow like blind people), right ?
Would an Intellego requisit (and an increase of +1 magnitude) solve this problem, by granting everybody present the ability to see what this spell turned invisible (and only this spell, it does not grant "See the Invisible") ?
Second question: turning a carriage or a small boat invisible
PeIm 20 makes on person invisible, +2 magnitude to increase target size to Room (so PeIm30) is it enough for a small boat (dinghy type) or a carriage ?
Third question: turning a building invisible, but not its habitants
Again, based on PeIm 20 +3 magnitude to structure (PeIm 35). This normally would turn a building and its content invisible. If the magus only wants to turn invisible the house itself, its content, but not its occupants should it increase the magnitude by +1 for higher control ?
My magus could see this spell as quite efficient to find intruders (yes, there are other spells to do that, but 1) he is not very practical - not that it dawned to him, 2) it bypasses any magical protection 3) yes, it will violate the privacy of sanctum, but did I mention he was not very thorough in his thinking process ?), or as a way to confuse people in their own building: they cannot see walls, closed doors, fire place and so on.
It has also other practical applications, like any sight spell becomes suddently more efficient, but it is more his sodales that will find that out.