T powering involves sending 12 volts up the mic line along pins 2 and 3 of the mic cable. Pin 1 is simply used for shield and ground. Phantom Power uses all three pins to send 9 to 48 volts of powering up to the mic. Some mics are advertised as being able to function at 9 or 12 volts Phantom. However, all of the premium condenser mics that I have encountered prefer and are rated for 48 volt Phantom.
Experience dictates otherwise.
Although most dynamic handhelds are not affected, the same is not true of electronic based mics, such as electret condensers and wireless. To make them work with non red-dot power supplies, simply use a reversing cable between the mic and the power supply. 3 goes to 2, and 1 remains connected to 1. The other parameter by which we classify shotgun mics is by the pickup pattern. Omnidirectional refers to hearing equally well in all directions.