in fact, there was another spice used in the study that went overlooked. well, i was only able to play it a little yesterday - i ran into a wall on a sharp turn... i had to retire from the race! too many tags, make for too many obstacles, thus slowing them down. i don’t have time to be switching various prime lenses, the 24-70 stays the my camera around 70% of the time. it's famous for eating its way through multiple layers, and its metal construction and serious motor are the very definition of "heavy duty." 