Nikon's WT wireless transmitters enable fast transmission of images – either automatically or by manual selection – direct from your camera to an FTP server or computer, and they also allow you to import IPTC photo metadata into the camera's memory before shooting, so the data is automatically attached to images as they're shot. This saves critical time for editors as well as photographers. They also enable a number of other useful functions, including camera operation from a computer via Camera Control Pro 2, and simultaneous release of multiple remote cameras from one master camera, depending on which WT transmitter you use.
The WT-4 offers wireless LAN for the D4 series. The WT-5 provides wireless LAN for the D4 series and the D5, as well as an optional HTTP server mode, enabling remote shooting and viewing of pictures. The WT-6 and WT-7 enable image-data transfer via high-speed wireless LAN for the D5 and D500 respectively, and both also offer HTTP server mode and FTP upload/camera control.
For photographers using the D4 series, D810/A, D750, D7200 or D7100 cameras, the UT-1 communication unit will provide an ethernet connection going from the camera to a computer or FTP server. In PC mode, you can even shoot from the laptop, providing it's running Camera Control Pro 2 software. For those same cameras, the UT-1 used with the WT-5A will also enable high-speed image transfer over wireless LAN to a computer or FTP server.
NB The letters A, B, C, D or E after the WT number indicates the number of channels available to the photographer, which varies across the world due to different regulations governing the use of wireless frequencies. The WT-5 and the WT-5A/B/C utilise IEEE 802.11 a/b/g/n while the WT-5D utilises IEEE 802.11 b/g/n.