Sigma EF-610 DG ST Flash
The newest addition to the Sigma line of flashes is the most powerful one yet, now offering a Guide number of 61 which translates into 61/m (200/ft) and designed to work with the latest TTL auto exposure systems of all the most popular digital and film SLR cameras. It features TTL automatic flash exposure control for easy operation. The auto zoom function automatically sets the optimum illumination angle in accordance with the lens’ focal length in a range from 24mm to 105mm. When the built-in Wide Panel is used, the flash can cover the angle of 17mm.