big problem with some older Nightvision Camcorders is that
the Infra Red light they give off to produce a lit image in
a pitch black location isn't strong enough, giving a dark,
grainy image that is sometimes very hard to see. That's where
IR torches become useful. If, for example, you're outside
and want to light up somewhere where, perhaps, a noise had
been heard, then an IR torch will be able to fully light up
the area when viewed through the camcorder but whilst also
keeping the area in darkness. Their only problem is that the
batteries don't last too long, so they can't really be used
to keep a continuous illumination for, say, a locked off camera.
However, they're perfect for quickly checking out anything
interesting without having to turn the lights on.