I checked the book before I did it...let my copy paste.
Page 258:
While a spellcaster normally hexes technology
as an accident of being a wizard (page 228), he
can also do it on purpose, focusing his energies
to disrupt electronics and other devices. This
is significantly less taxing than performing
other forms of evocation—you don’t even need
access to the Evocation power (page 180) to do
it, so long as you are some sort of practitioner,
because it doesn’t require command of any
particular element or force.
In addition, the
normal 1-stress cost for summoning power up
to your Conviction is waived, giving you a “free
shot” at most forms of technology.
As such anything up to 5 shifts of power I get a free shot on. Five shifts is quite a bit which would include lights, cameras, TVs, etc. Pretty much anything electronic in this bar. Only thing requiring more is SUPER old technology. Hell, fancy cameras would allow me to probably take out 5 at once using the 1, 1, 1, 1, 1 division...