Turning on a MOSFET takes more than knowing the threshold voltage. A special event occurs when a FET turns on, which is called the Miller Plateau. The gate voltage sticks to the threshold voltage while the drain opens up. In this video, James shows how to measure the Miller Capacitance, using an oscilloscope and custom MOSFET test board.
This video came from some measurements I did on a live stream. I had intended to demonstrate something else, but the board I created was such a great demo board for the Miller Effect.