... but I have used similar levers on zooms over the years. Even at their simplest, they can be immensely useful devices. With a steady hand, you can perform creep zooms that ramp up and down; with careful positioning of the lever you can 'preset' so your start/end point is easily recognized (top dead centre, for instance).
So colour me a big fan, though to repeat I haven't used this specific one yet.
