Qnexus links your Qflash to the wireless TTL systems of Canon and Nikon. Qnexus "reads" the Canon or Nikon wireless IR code to command Qflash in manual, automatic, TTL, and TTL-Ratio,when mounted to a Qflash5d-R. Use any number of dedicated, full-function Qflash 5d-R's as remotes controlled totally from your camera's master flash menu. Qnexus supports all Canon and Nikon wireless flash functions from as far away as 100-200 feet! * Qflash 5d-R equipped with Qnexus gives you an additional 150 to 400 watt-seconds of beautiful, studio-quality lighting to dramatically expand your creative options. For example: make a great portable portrait set-up by using a Qflash in a softbox, or with an umbrella as your key light, and use your Canon or Nikon flash for fill. For those tricky large group photos, use multiple Qflashes for more lighting power, all controlled by a Canon or Nikon on-camera master flash. You can even mix remote Canon/Nikon flashes with remote Qflashes. You are not limited to the power of shoe-mount flashes! Get Qflash power, light quality and seamless integration with your Canon or Nikon wireless flash systems. *Maximum distance for direct line of sight may vary due to type of master flash or control unit used. Supports all dedicated Canon and Nikon wireless flash functions including Manual, Automatic, TTL and TTL-Ratio. Supports all dedicated Canon and Nikon wireless flash functions including Manual, Automatic, TTL and TTL-Ratio. Qflash portable flash units deliver 150 to 400 watt-seconds of studio quality lighting with no limit to the number of wireless Qflashes employed. Qnexus-compatible factory upgrades also available for Qflash 4d and 5d models.