Nikon D810 User Manual page 286

D
During Transfer
Movies can not be recorded or played back when the UT-1 is
connected and there are either images remaining to be sent or images
currently being transferred via an Ethernet or wireless network.
A
Movies
Movies can be uploaded over Ethernet and wireless networks in
transfer mode. Note, however, that movies can not be uploaded using
the Auto send or Send folder features in the Options menu.
D
HTTP Server Mode
The camera can not be used to record or view movies in HTTP server
mode.
A
WT-5 Wireless Transmitters
The principal differences between the WT-5 and WT-5A/B/C/D/E is in
the number of channels supported; unless otherwise stated, all
references to the the WT-5 also apply to the WT-5A/B/C/D/E.
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