DJI's SDR Transmission II carries 4K60 HDR video 2.5 miles at 349 euros a radio

A director asks for camera B. Under the arrangement DJI is replacing, that meant rebooting the receiver and searching for the other transmitter ^[5]. The new system makes it a tap, at latency DJI puts as low as 35 milliseconds for commands like focus pulling and gimbal moves ^[5][6].

The picture upgrade is narrower than the spec line implies. Bitrate went up 2.5 times, from 20Mbps to 50Mbps ^[15]. Taking 4K as 3840 by 2160, the pixels per frame went up four times ^[16], and 4K at 60 frames a second is about 498 million pixels a second, which puts 50Mbps at roughly 0.1 bits per pixel ^[17].

DJI describes the job in matching terms. The system provides monitoring for directors, producers and set personnel, with smartphone monitoring plus assist tools including focus peaking and waveforms ^[9][10]. It "lets camera operators and focus pullers remotely adjust settings and control the camera," DJI said ^[8]. It also supports PTP control of capture, aperture, shutter speed and ISO on compatible cameras ^[11].

On range, the underlying figures are 3 km to 4 km, a third further, which Engadget renders as 1.8 miles to 2.5 miles ^[18]. DJI says that with the new system "a reliable link can be established in various environments from open stadiums to dense mountain forests, and through demanding car-to-car shots or challenging FPV drone work" ^[7]. Engadget did not publish the conditions behind the range or latency figures, or say how they hold with 40 receivers on air.

Pricing is per radio, and that is where a multi-camera plan gets expensive. Transceivers start at 349 euros, or 309 pounds, with a two-pack at 629 euros ^[12]. The largest configuration DJI quotes is five transmitters and 40 receivers running at once ^[4], which is 45 radios ^[19]. Bought as 22 two-packs plus one single, that is 14,187 euros before any camera bodies ^[20].

None of it is orderable in the US yet, and Engadget attributes that to a ban on certain DJI products ^[13]. A US-based rental house cannot standardise a monitoring workflow on hardware it cannot buy. The radio family underneath is the same one in DJI's drones, OcuSync ^[14].

Two questions sort the camera positions on any given day. First, does the camera move in a way a cable cannot follow, such as a car-to-car rig or an FPV drone ^[7]. Second, is the feed being looked at or being recorded. Positions that move and only need looking at are where a 349-euro radio does more than a cable: the director's monitor, the focus puller's pull, an ISO change from the cart ^[8][11]. A single transceiver reaches up to eight others, each supporting remote control, so a modest rig is four or five radios ^[3]. For static positions, and for any feed that has to be recorded, the cable stays; DJI is selling the link between the camera and the people watching it ^[9].