"Hot shoe
From Wikipedia, the free encyclopedia

A hot shoe is a mounting point on the top of a camera to attach a flash unit.

Design

The hot shoe is shaped somewhat like an inverted, squared-off "U" of metal. The matching adapter on the bottom of the flash unit slides in from the back of the camera and is sometimes secured by a clamping screw on the flash. In the center of the "U" is a metal <B>contact point</B>. This is used for standard, brand-independent flash synchronization. Normally the metal of the shoe and the <B>metal of the contact</B> are electrically isolated from each other. To fire the flash, these two pieces are shorted together. The flash unit sets up a circuit between shoe and <B>contact</B>—when it is completed by the camera, the flash fires.

In addition to the <B><I>central contact point</I></B>, many cameras have additional metal contacts within the "U" of the hot shoe. "