There are two effects from the Hermetic Projects book (Stone Watchman & Fingers for Eyes) that use Inteligo Imaginem to view a distant area. They both claim that the user of the spell or effect will not be able to see creatures in the area with MR that the effects do not penetrate.
This contradicts (or seems to contradict)
Prying Eyes (core book page 144)
To See as Through a Plethron Distant (MoH 101)
View from the Mannequin (LoH p 113) (quite directly as this spell specifically notes the ability of the user to see targets with MR)
and quite possibly a few other spells.
My present understanding is that the effects collect the mundane visual species of the target area. So, while they might need to penetrate a creature's resistance to see from a creature's location, they shouldn't need to penetrate to collect mundane species that are emitted by a creature with magic resistance.
Is there some subtle difference in the new spells that makes them function differently? Is there a compelling argument why the take the line has followed up to now should be changed? Or was this just a mistake?
I'd especially like to hear from Mr Lawford or Mr. Love if they had a specific aim in doing these spells differently.
Okay, I'm doing this from memory but I think the key difference is in the Target.
The Stone Watchman (I think) has a T:Vision effect on it, while Prying Eyes is a T:Room. The Vision Target actually provides a form of magical vision to the Stone Watchman - without it the Watchman is blind.
I think the way to imagine it is that the Vision effect sends something active out from the bearer of the effect and it collects the information that this medium bumps into. Given that these Vision-waves are magical, they need to penetrate in order to return any useful information. Why then, does the black absence of information resulting from a failure to penetrate not get reported back? Good question. You get an extra point for asking it. It's because telling you that there is a big black dragon-shaped hole in your field of vision is telling you something (something quite useful too) - it would be reporting information back, which it can't do as it failed to penetrate. It isn't radar or sonar or lidar or any other kind of --dar. It's magical Vision.
Prying Eyes on the other hand relies on information provided by the actual species in a room. There are no magical Vision-rays, only natural species that the magic detects and informs the caster about.
Does that make sense? I mean, as a distinction is that clear? I'm sure there will be some who disagree with the way it works, but it is an important distinction that I do remember being discussed at the time.
Sorry, should also add as Plethron was mine too...
Plethron works in the same way as Prying Eyes except it uses a Special Target for additional flexibility. So again, that only collects information on the natural species rather than sending out Vision-rays.
The thing to note about this spell (and others that work the same way) is that you cannot then cast magic against Targets sensed through this layer of magic. The write-up of the spell actually provides in-game flavour text to explain the real-world decision made during the development process.
Hmmm. I'm afraid that I find that logic, whilst internally consistant, to be difficult in its implications specifically because it is Imagimen. For a start, the gift of magical vision (Vision target) is more normally associated with spells which allow you to detect a true form, or see Regio boundaries or the like, and as such may be regarded as creating a proxy (the sense) which casts the spell repeatedly at everything observed and then reports back - clearly these effects do need to penetrate. InIm, however, specifically targets species and whilst magical species do exist, the species emitted by things both mundane and magical are mundane unless otherwise specified. The InIm spells do not target the emitters of the species, but the species themselves. The effect you describe would be a convoluted InCo(Te)(An)(He)(etc) effect since it targets the emitters rather than the species themselves.
Well, you could assume that as it provides additional information, like an overlay; the absense of additional information is not noticable. For myself, I'd just argue that species aren't light and don't work that way - PeIm doesn't create a black void, so presumably the species of the things behind you, not being overwritten, behave as normal.
Imaginem is a fiddly enough Form as is with the disctinction between species and the emitters thereof (CrIm illusions, anyone?). Out of interest, does anyone have a feel for the MuIm guideline to render a targets species magical and thus grant selective invisibility to an item? My gut is that it should be fairly low, balance be damned, but I suspect others will disagree.
 Hmmm. Sensory spells as a potential feedsource for Hermetic Theurgy; Daemons as daemons.
Good question. My read is that there is no contradiction.
ArM5, page 114 (1st column, 2 paragraphs above "taste") states that "magical senses must penetrate the Magic Resistance of creatures sensed". My read is that all these effects (including Stone Watchman & Fingers for Eyes) give the caster some sort of magic sense.
Prying Eyes and To See as Through a Plethron Distant don't mention penetration at all, so they just implicitly follow the general rule that magic senses need to penetrate.
The Discerning Eye explicitly talks about needing to Penetrate (and therefore using lack of Penetration as a way to infer the presence of unsensed things).
My reading is that, unfortunately, View from the Mannequin is the one that is inconsistent, and is either wrong or for some reason not a standard Hermetic effect.
Ignore the mumbo-jumbo about species, that's just flavour text. The important bit is what the rules say happens, and the rules say that magic senses need to penetrate. This is reminiscent of the "wards need to penetrate" issue. The rules state this, but then most individual ward spells don't bother to remind the reader. Same thing here: magic senses need to penetrate, but some individual spells don't contain reminder text of this fact.
They aren't magical sense spells. They use the casters non magical senses at a new location. They're done by the Intellego imaginem guidelines using non-magical sense targets.
Mark hit the nail on the head when he noted that the stone watchman was a magical sense spell using "vision" as the target. In retrospect since it mentions it is a magical sense spell explicitly in the description I was foolish to have missed it.
I've not previously thought that normal senses should be included as magical sense but now that it comes up I'd rather have magical abilities broader than narrower so I've got no complaints on that one. (I'm intending to check the core book to see if you can fit "normal" sight into the definition of a magical sense spell. I've not yet had a chance to do so, I might still have an issue.)
The big deal here is that Prying Eyes, To See as Through a Plethron Distant, and View from the Mannequin are not magical sense spells.
The question is what target did you use? If it's target vision, everything should be fine. If its not I think that the Discerning Eye may well be in error.
This I cannot disagree with more strongly. The rules are a patchwork mishmash of ideas over decades representing many conflicting visions. The flavour text represents what the rules are trying to represent, the world of Mythic Europe and all its attendent foibles, and without that vision interpretation of the rules is directionless. Now it's true that this is a back-and-forth, with proposed rules shaping the world and vice versa, but you cannot just dismiss the setting. A&A remains my favourite 5th edition supplement because it talks about the underlying world and how it functions, and thus how Hermetic magic may be used to work within it.
As for wards-needing-to-penetrate, that perfectly represents my point - prior editions had penetration as casting total, and so wards effectively did not need to penetrate, the level was what mattered. In 5th edition, penetration is derived and thus the double-cost appears. I quite agree that wards should penetrate, but the RAW retain their old form with odd results, much as with he fact that it's easier to ward against low-level demons than your apprentice.
By the RAW, they are not. The rules are really quite specific. Whether that's a good thing or not is a different matter.
Except, and this is the crux of the matter, the creatures are not sensed because the spell does not target them. It target species. InAn(Vision) would target magical wolves, letting you see (detect with vision, rather) them even if invisible, and this would have to penetrate.
Except it, um, doesn't. It provides him with knowledge of what is on the other side of the walls, rather than letting him see through them. Specifically, it grants him knowledge of the entirely mundane species. An InAn(Room) spell to detect the presence of animals in the room in question would need to penetrate as it targets the animals themselves, but it too does not grant a magical sense, but rather knowledge gained magically.
The statement you quoted earlier about magical senses needing to penetrate was taken from the middle of the description of magical sense targets where, as I quoted, magical senses are specifically defined as using magical sense targets.
An Intellego Animal spell targets the Animal, and fails if that Animal is protected by sufficient magic resistance.
Intellego Imaginem spells like Prying Eyes target the species (that's why the form is Imaginem), and those are rarely protected by magic resistance even if the subject "shedding" them is. One situation when Prying Eyes is resisted is when an apprentice tries to figure out what his master's familiar has just gobbled up and is hiding in its mouth by touching the familiar's cheek (the mouth counts as Room). But if the familiar is in a room and the apprentice casts Prying Eyes on the room, he should generally see the familiar (barring invisibility etc.).
I'm not sure I fully understand what you're asking, but the approach that I take (and supported by effects like Stone Watchman) is that to give an object senses you need to use the sense Targets (Hearing, Vision, Smell, etc.)
ArM5, page 113 and 114 give you all you need really.
The InIm base guideline is only 1 as that allows you to use a sense at a distance.
So assuming you want a box that has the power to hear normal sounds (I don't know why, but you want one) I think it looks like this:
The Eavesdropping Box
R: Personal, D: Sun, T: Hearing
Grants a box the magical sense of hearing.
(Base 1, +2 Sun, +3 Hearing; +1 2/day, +3 triggered at sunrise/set, +21 Penetration of 42)
Required Lab Total: 1 season (70), 2 seasons (53), 3 seasons (47), 4 seasons (44)