Canon Rebel T2i Quick Start Manual page 107

Shure SM 58 Dynamic Microphone
The Shure SM58 is a dynamic microphone.
It does not require power to operate.
The dynamic microphone has a low volume
output so it will require more input gain than a
condenser microphone.
The SM58 has a cardiod polar pattern and is a
great choice for voice recording in an
environment where you cannot eliminate
background noise. It will only pick up sounds
very close to it.
The heart shaped cardioid pick-up pattern
requires you to place the microphone close to
your mouth.