We recently did a rotating shot transitioning from a 1910 candlestick phone to a smart phone. We used our 25 year old, 20lb. turntable with a 700lb. capacity hooked up to a variac, (I could have used any portable lighting dimmer). The variac let us set our speed and the heavy turntable was rock solid smooth. We were able to slow the turntable to about a 30 second rotation.In post we made minor speed corrections for the timing we needed. The tricky part for us from a lighting stand point, especially with the very shiny smart phone, was that this was a green screen shot. Lots of large soft bounce light, flags and distance from the green...
Mark D'Agostino
http://www.synergeticproductions.com