Owner of Nikon D7100, the built-in is lacking for what I want to do. For budget flash I was recommended Yongnuo YN560 IV: YONGNUO YN560 IV YN-560IV Wireless Flash Speedlite Master + Slave Flash + Built-in Trigger System for Canon Nikon Pentax Olympus Fujifilm Panasonic Digital Cameras No problem there, looks good, but I am trying to sort through some confusion...I want the piece to attach to the camera that will trigger the flash from off the camera. IV model is supposedly III + TX (Ref. from Amazon description: "YN560 IV=YN560III+YN560-TX, Supports Wireless Master Function") -- but they also sell 2 types of TX separate :: YONGNUO YN560-TX Flash Transmitter Provide Remote Manual Power Control for YN-560 III Manual Flash Units Having Manual RF-602 RF-603 RF-603 II Compatible Radio Receivers Built In YONGNUO YN560-TX LCD Flash Trigger Remote Controller for Nikon and YN560-III With Wake-up function for Nikon cameras I'm trying to sift through the confusion of all of this to get the pieces I want. I want the flash and the piece required to dismount the flash and trigger it remotely, say if I were to prop the flash up in the sand or on a tree. Please advise, any help greatly appreciated!