[baakyocalder]

Think of Correspondence 2 (Data 2 for Technocrats) as letting you extend your senses and make small changes when combined with other spheres to objects in space.

So, with Correspondence 2, you could see or hear someone else, and not need to worry about light.

With Correspondence 2 and Life 2 or Matter 2, you could move small living or unliving objects.

Forces 2 allows control of existing energy, be it light or sound. To communicate with someone from afar, use the Correspondence 2/Forces 2 effect to manipulate the light or sound around them and understand their response to your signals. For example, you could send an SOS using light patterns on a billboard.

I'm using Correspondence in Mage 2nd edition. Mage Revised tends to make magic harder and although the current edition, Mage 20th Anniversary is a tome filled with many bits of information on magic, it's pretty vague on what effects occur or goes baroque in Mage 20th Anniversary How Do You Do That?

It's always best to think less about the spheres and more about how the magick is going to happen. What is the desired effect and what does the mage see as happening. Typically this means most complicated actions require more than one sphere, but it's not that much harder to do multi-sphere magick if you have the spheres.

For an Arete 6 person using Correspondence on a family member or other well-known target, they will roll because you need more than one success to affect others, but should succeed most of the time on rank 2 effects.