If the 'Full Frame' body was using a 24-70/2.8 lens and the 'APS-C' body was using a 16-50/2.8 lens, they would both be capable of almost identical images, but with an aperture of f/2.8 and a subject distance of 7 feet, the 'Full Frame' body would have a DoF of 0.5 feet and the 'APS-C' body would have a DoF of 0.66 feet, about what the 'Full Frame' ...
A Double Pole Double Throw (DPDT) switch is a switch that has 2 inputs and 4 outputs; each input has 2 corresponding outputs that it can connect to. Each of the terminals of a double pole double switch can either be in 1 of 2 positions. This makes the the double pole double switch a very versatile switch. With 2 inputs, it can connect to 4 different outputs or reroute a circuit into 4 different modes of operation. A Double Pole Single Switch is actually two single pole double (SPDT) switches.
It allows one to look around in one's virtual world, browse menus, etc. For example, many flight simulators use it to switch the player's views, while other games sometimes use it as a substitute for the D-pad. Computer gamepads with both an analogue stick and a D-pad usually assign POV switch scancodes to the latter. The term hat switch is a shortening of the term Coolie hat switch, named for the similar-looking headgear.