Yeah, there seems to be some confusion here between 'transparent,' 'unreflective,' 'non-absorbant,' and 'invisible.'

Something that's transparent can't be seen because light passes right through it. This would pose a massive problem for vision, because you need to capture light to see things. This is what would lead to the scenario with an invisible 'van' and visible occupants. Some sort of rule or principle would define what constitutes the 'van,' and the occupants wouldn't qualify, so you couldn't see the van but you could see its contents. Transparency is also the most likely explanation for being inside the van and being unable to see the controls/occupants, if all were rendered equally transparent. A transparent object may or may not be able to emit light from a source (eg, brakelights); I'm not really up on my physics for that, but I suspect the brakelights/headlights/etc would still work (as would any dash lights, which could be kinda freaky). Of course, it's hard to imagine a physical object which is both transparent and possesses the necessary properties to generate light, so, dunno.

Unreflective objects don't reflect any light, and non-absorbant objects don't absorb any. Bending light away from/around an object effectively gives it both properties. Having the first without the second would give you a pitch-black object with a moderate-sized shadowy region about it. Having the latter but not the former would give you a very shiny object, moreso than a mirror (but maybe not 'reflective' in the sense you think of when you think of a mirror, because the light might be reflecting at all crazy angles unless the surface is very smooth). Having either property would make conventional vision for that portion of the electromagnetic spectrum impossible, but hey, this IS magic.

Invisibility is the state of being non-detectable within that range of the spectrum. There are a wide variety of ways to accomplish this; in Ghost in the Shell, we see 'invisible' characters who (unless I misunderstand -- I've only really watched the SAC series, which doesn't go into explanations) accomplish this by simply editing out their existence from other people's perception in realtime, a form of mind/perception control. A godlike technomancer could do this, and would be invisible to anyone with cybereyes and to machines. (Note that a godlike technomancer would probably be able to remotely activate devices which have a wireless connection but aren't set to broadcast. This can already be done to a certain extent using some really crazy electronics, but you need to know certain things about the device you're targeting) A mage could do this and would be invisible to anything with a 'mind.' Alternately, you can have a realtime chameleon effect, where the reflective/absorbant properties are adjusted quickly to perfectly simulate the surrounding environment.

Or you could just define a state 'Magically invisible,' and give it the properties 'cannot be visually detected from the outside.' I like this solution, and it's what I use, unless I'm feeling sadistic or humorous enough to do some of the other things described in this thread.

Yeah personally I'd treat it basicaly like an 'advanced' ruthinium coating, at least to a degree. Except that with invisibility your actual speed wont matter as it's not some bit of technology trying to keep up with the constant changes, but simply a magical spell that basically says to what ever it can that 'Umm.. yeah btw. Not here! BYYEEEE!' and then the subconcious response being "Oh.. well ok then. These arent the droids we are looking for."

Since mana invisibility edits the sensory input at the mind of the target, I see no problem with allowing physical invisibility to edit sensory input at the eyes of the target.

The magic through the television problem does not exist at all, because it can't be done by canon. If a television camera records an invisible character then a person can see that character by looking at the recording. If the spell defeats the camera then it it doesn't record anything.
Unless you are looking at the subject of the spell directly with your own eyes while the spell is being sustained you are not a target of the spell.

By the way, the camera also causes problems. If an II spell does not defeat the camera's OR then the camera record the subject as if the spell was not cast at all. This makes no sense if the light bends around the subject but it makes perfect sense if the light is edited in the camera.

But like I said, there are a few relativistic problems with this model, mainly area of effect. As written, the spell affects the physical properties of the character's image. If that's the case, then this will be true no matter how far away the sensor is. If it's not the case, then how far away does the magic 'reach'? Can an orbital camera detect the character automatically? Could a powerful enough sensor on Mars? The rules say no, the spell doesn't have an area of effect. However, if the effect occurs at the sensor, the effect has an area of effect around the character. Are you arguing that magic can have an unlimited AOE? If I can edit the perceptive properties of a sensor at any range, why can't I, say, ignite a sensor at any range instead? The magic's 'crawling out of the box,' it's travelling far beyond the limitations of what it ought to be able to do, under that interpretation.

I'd also like to point out that the rules as written affect whether or not a technological sensor notices the character, not whether or not it records one. That is, I'd say someone watching the film of a camera taping an I.Invis Mage would have to make the perception test, not the camera to record it at all. If there's an automated system linked up to a camera, then it has to make the opposed test in order to 'notice' that the character is an anomaly rather than just a dust pattern or whatnot. In either case, the sensor records the actual effect -- the character's partially visible form -- but how 'noticable' they are to human or technological reactive criteria is dependant on the Opposed Test score. The Object Resistance test is likewise given to the reactive system (not the camera) as a representation of the fact that an object won't be decieved by the same sorts of optical illusions a living being, with its feedback-based perceptive system, would be. Eg, shadows, light changes that alter depth perception, et cetera, won't fool a computer, even though they're purely physical effects.

OK, what's the difference between having a spell that makes things not percieve you by editing the input of light at the target sensor and a spell that makes things not percieve you by editing the input of heat at the target such that the sensor bursts into flame?

In other words, we're talking about a Basilisk spell -- something that affects any sensor that happens to pick up the object (not subject) of the spell. That seems to really conflict with how magic works in SR.

The difference is that a spell that makes things burst into flames wouldn't be an illusion.
And you shouldn't forget that the mana version of the spell does the same thing, it just does the editing in the mind rather than in the eyes.