Sigma line of flashes is most powerful one yet, now offering Guide number of 61 which translates into 61/m (200/ft) and designed to work with latest TTL auto exposure systems of all most popular digital and film SLR cameras. Advanced features and high performance allows photographers to express their intentions accurately. EF-610 DG SUPER's auto zoom function automatically sets optimum illumination angle in accordance with lens focal length in range from 24 to 105mm. When built-in wide panel is used, flash can cover an angle of 17mm. For bounce flash flashgun head can be tilted up by 90 degrees, to left by 180 degrees or to right by 90 degrees. It can also be tilted down by 7 degrees allowing ease of use for close-up photography. Among advanced features of this flash is modeling flash function, multi-pulse flash, TTL wireless flash, FP (high speed) flash, rear-curtain Synchro flash and manual flash mode, which allows photographer to set flash power level by up to eight stops. Auto power-off function automatically shuts off LCD panel to help save battery power. When flash gun is fully charged, confirmation ready light will be emitted.