How does the Duck Hunt game work for the old Nintendo?

Factual Questions
1

It’s been bugging me for a while…

2

The master has spoken:

http://www.straightdope.com/columns/010511.html

3

The best way to cheat at Duck Hunt is to turn your brightness knob all the way up.

IIRC, newer light guns (Such as the Guncon2) are much more sensitive and actually can tell what you are “shooting” at.