Jam-packed with features and functions, the YN568EX III Speedlite from Yongnuo is a stellar addition to nearly any lighting kit. This model is directly compatible with Nikon's i-TTL system, permitting espandi... on-camera use with automatic exposure capabilities and high-speed sync. It can also function as an optical TTL slave for either Canon or Nikon systems. It is quite powerful as well with a rated guide number of 190' at ISO 100 and 105mm and is versatile thanks to a head that can tilt from -7 to 90° and rotate 270°.