With a notably slim, compact design and ADI / P-TTL support, the HVL-F20M External Flash is ideal for those looking to add a little fill light to their images or for use as a wireless TTL controller for off-camera flash units without adding too much weight to their gear bag. It offers a modest guide number of 66' at ISO 100 and 50mm along with two coverage settings for 27mm or 50mm with full-frame sensors. Also, the unit can tilt the flashtube upward 75° for achieving softer, more diffuse bounce lighting.