Mage Sight is the ability of mages to detect Mysteries and other supernatural phenomena. Despite the name, it does not necessarily manifest visually, or not exclusively visually, and its form varies depending on the Path of the mage in question and which Arcanum they are using.
Degrees of Mage Sight Edit
Peripheral Mage Sight Edit
To some degree, Mage Sight is always "on" once a mage is Awakened. Without expending much effort or concentration, they can detect the active presence of supernatural phenomena around them, although even rudimentry supernatural concealment will fool it. A ghost or spirit using a Numen, for example, will always register to any mage, but not one simply dwelling in Twilight.
Active Mage Sight Edit
To actively study one's surroundings through Mage Sight requires concentration. Mages can automatically use the Ruling Arcana of their Path as the "lens" through which they use Mage Sight, and with a bit of Mana can use any other Arcanum as well. The Arcanum in use can influence what can and cannot be seen--for example, using the Death Arcanum allows the mage to see ghosts when they're not using a Numen, and to identify if a human body is actually dead or alive (which may allow them to recognize a vampire).
Active Mage Sight is mentally strenuous, and costs Willpower to sustain over more than a few minutes.
Focused Mage Sight Edit
In order to study a particular target in-depth, Active Mage Sight can be intensified to Focused Mage Sight. This cannot be used to scan a broad area, only to look at a specific target, and comes in two forms: an instant Revelation or a prolonged Scrutiny.
Revelation reveals relatively "surface" information about a Mystery, such as whether it was caused by Awakened magic and its age. Scrutiny reveals more in-depth information, such as the Nimbus of the caster, whether Paradox was created, and how the Arcanum used for Scrutiny relates to the Mystery. For example, while active Mage Sight through the Death Arcanum could potentially detect a vampire, Scrutiny could reveal a ghoul.
This kind of close study is not a passive process, however--it absorbs the mage's entire attention, and floods the area with energy, which can in turn attract the attention of other mages or dangerous Abyssal entities.