Hi - the DVX100 has three zoom setting. Manual, Auto and infinity. Easy to put into Manual and auto as the level/switch locks but how does one get it inot infinity? The switch/level does not hold
You can't make the swith stay in infinity setting. One push on it makes the camera change it's focus to infinity (far away focus). It's used if you quickly want to jump from a closer focusing point to infinity without turning the focus wheel.
I use that switch to calibrate to a mark on the lens barrel. Line them up, press the infinity button, then you can have repeatable focus marks. Takes a trip to office depot to get some thin white tape, and possibly some white nail polish.