Here's a quick picture from the Profoto B1 using its built-in HSS mode. HSS lets you shoot at sync speeds far higher than usual. This was shot at f2.2 at 2000/s.
A.C. Grayling, philosopher, and author of 'The God Argument', attends the Hay Festival of Literature and Arts on May 23, 2015 in Hay-on-Wye, Wales. The Hay Festival is an annual festival of literature and arts which began in 1988.
More conference photography.