The EF-530 Super DG is Sigma's flagship TTL flash, and has been updated with improved coverage range and a stronger power output. It has a Guide Number of 174'/53m at 105mm, and covers a focal range from 24mm to 105mm. The EF-530 unit is fully compatible with the lastest DSLR and supports TTL operation, including full ADI operation with compatible cameras. The EF-530 DG SUPER employs several convenient functions, including the "Multi-Pulse Flash Function," which exposes a series of images onto a single frame, and the "Auto Power-Off Function," which automatically shuts off the power. It also features a red-eye reduction function, an exposure compensation function, an exposure-control checking function, and many others. A perfect all-around flash for any digital or 35mm autofocus SLR shooter.