So somebody with a better understanding of sensory species in the paradigm, please help me. Do reflective surfaces absorb species and re-transmit them as new species, or do they truly reflect existing species?
This is mostly for visual, but imagine that it could include auditory species.
I also wonder how this might affect hermetic magic, specifically for Voice and Sight range spells, if magi can target people with the reflections - especially with Sight spells, can you target someone with a Sight spell from their reflection? Does this count as perceiving the target for the purposes of casting Hermetic magic?
Additionally, I wonder about the magic necessary to create reflective surfaces, especially perfectly reflective ones. I could see this as a Muto (Form) applying to each target (so, Muto Terram to make a wall into a mirror), but I could also see this as either a function of Muto Imaginem (change the image of the wall into a reflective image) or Rego Imaginem to make the species bounce (and this could violate the whole angle of incidence and reflection part of reflections as well). Imaginem is supposed to deal more with images than directly with species, at least going by the Core rulebook, I know the Jerbiton part of Societas deals a bit more with species directly, so I'm assuming that overrides Core.
I don't have any great answer here right now. The one thing that springs to mind, though, is Perseus and Medusa. Perseus used a reflective shield to see Medusa safely. While that could be just a Faerie thing or similar, it could well fit into the mythic part of Mythic Europe. Not sure if it does, just thought it was worth mentioning.
Some objects reflect light but not images, some reflect images. In teh second case the species are clearly reflected. It may not apply to sound since everyone knows that echoes are the purview of disembodied nymphs (myth of Echo).
A species does not advance in the medium by locomotion; it regenerates itself in consecutive parts of the medium.
If you accept Roger Bacon as the basis of ArM5 sensory species this implies, that sensory species don't really have an identity and that it is a moot point, whether reflected sensory species are 'new' or still 'the same'.
We know in ArM5, that there are magically created or copied species which are still magical, and these can be distinguished by magic.
Using a mundane mirror this should be the case. But using spells like MoH p.101 To See as Though a Plethron Distant is not: there iconic species are recreated and changed by Hermetic magic.
Unclear. In general, one cannot assume that a medium constantly absorbs and regenerates species, as Bacon assumed, or many of the spells in the Jerbiton chapter of HoH:S would not work as stated (unless you assume that mundane species and magical ones operate with different physics, which is itself problematic). For consistency, I would then also assume that species actually bounce on a mirror, are deflected by a lens or pool, etc.
Again, very tricky. When my troupe started playing Ars Magica 5th edition this was debated at length. We just decided that there would be far fewer edge cases, uncertainties and possible abuses if we interpreted "Sight" as "Direct, straight line of sight".
Note that this is not necessarily tied to whether species bounce on reflective surfaces, or are first absorbed and then regenerated; the two issues can be decided independently.
Why? Bacon has species move - but not by locomotion. And he does not call species full things. That understood, I don't see problems with reading about sensory species (magical and not) in ArM5: not even in the curious Scattering LIke Light (HoH:S p.63) temporarily transforming metal (with substance) into species (without substance).
It is not more tricky than transforming a Mind (no Substance) into a bird (with substance) for some time with ArM5 p.149 Inmost Companion.
This is excellent evidence that species (in Ars) do actually reflect off mirrored surfaces, as the spell takes advantage of that property to allow the non-reflective item to absorb the transformed species as a form of metal coating once the spell wears off.
I agree it's very tricky. However, we do have the 'Line' range from Hermetic Geometry, which gives the range of Sight magic but doesn't require the magus to see the target so long as they can sense them in some other fashion. And the Limit of Arcane Connection only applies to un-sensed targets, it doesn't define which sense, so targeting someone by sound and using Voice Range on them seems valid on its face. Targeting someone by their reflection probably gives you a better idea of their location than just listening to them, but strictly speaking you wouldn't be able to use Sight range, as you're seeing their reflection, not them.
If it's just normal hermetic magic to target someone with Sight range magic via a reflection, well, it works both ways. This is more valuable against mundanes than other magic users, though it might mess with magi using the School of Vilano to throw rocks at things. It might also require Perception rolls to be able to even spot things in a reflection (often more difficult than direct line of sight due to the quality of the reflection and extra distance involved).
If it requires a special Range (Reflection), this is probably covered under non-standard RDT guidelines. Range Reflection might require you to target a reflection, or it might be +1M more difficult than Sight, at least until someone did Original Research to bring it into Hermetic Theory as normal (this is probably how Range: Line got created, but they decided to keep it a mystery ability rather than share it with Hermetic Theory at large). This version gives the caster a bigger advantage given that the target can't cast magic back at you so easily, but it also requires you to invest in additional magic to get a decent reflection going, as most places won't have great reflective surfaces to play with.
So, for the moment, it seems that:
1.) Visual species are actually reflected by a reflective surface (and probably the same can be said for echoic species)
2.) Using Sight spells with mirrors might not be legal, but you can probably use a mirror to sense someone for other spell ranges (Voice mostly).
Personally I lean towards allowing Eye and Sight to be used with mirrors, but I can understand how people would feel that seeing someone's reflection isn't the same thing as seeing them directly, but it definitely requires set up to pull off and the quality of the mirror in question is probably a factor.