Zactrack vs BlackTrax: radio or optical performer tracking
UWB radio or infrared optical? The answer turns on haze, sightlines, what performers wear, and which departments consume the data.
What you’re deciding
Both systems put a fixture on a moving performer without an operator chasing them, and both will talk to your console. The decision is not which one tracks better in the abstract. It is which sensing method survives your venue and your show. Zactrack is ultra-wideband radio: performers wear tags, anchors read them, and nothing about haze or a scenic wall changes that. BlackTrax is infrared optical: beacons on bodies and objects, cameras overhead, and a data stream that carries orientation as well as position and reaches video departments as naturally as it reaches lighting. You are really choosing between a system that is indifferent to what it can see and a system that sees more when it can see clearly.
Haze, sightlines and scenic occlusion
This is the first question, because it can end the conversation. Optical tracking needs its beacons seen; heavy haze, low-trim scenery, deck-level pockets and crowd mass all eat sightlines, and the answer is more cameras in more places. Radio does not care what the camera cannot see, which is why it holds up in fog-heavy concert environments and inside built scenery. The counterweight: radio wants a well-designed anchor topology, and that placement is where accuracy is won or lost. Neither method is plug-in. Optical shifts the design effort into camera coverage; radio shifts it into anchor geometry and calibration.
What the performer has to carry
Both approaches put something on the body. Zactrack uses radio tags; BlackTrax uses infrared LED beacons, which also need to be visible rather than merely present, so a beacon buried under a coat is a beacon that has stopped working. That distinction drives real wardrobe conversations: housing, mounting, quick-change strategy, and whether the hardware disappears into the silhouette of the show. Optical beacons additionally go on props and scenery, which is often where their value shows up. If costumes are heavy, period, or change fast, work the wearability question with wardrobe before the platform decision hardens, not after.
Position, orientation, and what video needs
Zactrack delivers position, which is what a fixture needs to point at a body. BlackTrax delivers position plus orientation, so an object that rotates as it travels reports which way it is facing. If nothing in the show rotates meaningfully, that data is unused capability. If projection has to stay locked to a moving surface, or a real-time engine needs an object pose rather than a point, orientation is the whole reason to be there. Worth noting the neighbouring option: VYV Copernic is also optical and projection-led, and belongs in the comparison whenever video is the primary consumer rather than a passenger.
Which departments are downstream
Ask who subscribes. Zactrack can feed sACN or PSN straight to the desk, or route through a translation layer when the show merges several position sources, and that is a short path when lighting is the consumer. BlackTrax streams over RTTrP, which major media servers and real-time engines consume directly, so lighting and video ride identical numbers rather than two systems that agree most of the time. The more departments in the list, the more the integration work moves upstream into coordinate alignment and routing, and the more the choice is about the data bus rather than the sensor.
Walk it in this order. First, stand in the venue and ask whether overhead cameras can see every place a tracked performer goes, under show haze, with scenery in. If the honest answer is no, choose radio and stop. If the answer is yes, ask who consumes the data: lighting alone points to radio for the shorter path; lighting plus video plus a real-time engine points to optical, because one stream serving every department is worth more than the marginal ease of deployment. Then ask whether anything rotates in a way lighting or projection must respect. If yes, orientation data is decisive. Finally, take the surviving option to wardrobe before you commit.
Can we run both on the same show?
Yes, and merged sources are common on complex shows. Position data from more than one system can meet on a translation layer that presents the console with one authoritative set of coordinates. The real work is not the plumbing but the agreement: aligning coordinate spaces so both systems describe the same stage, and deciding per cue which source is authoritative when they disagree.
Does either one remove the followspot operator?
Both can, for the cues where continuous automated pickup is what the show wants. Neither should when timing is the point. Unscripted moments, comedy beats and ad-libs are where a human in the loop outperforms any system tracking a body correctly but reacting to nothing. Plenty of shows run automated tracking under the bulk of the show and keep an assisted followspot for the moments that need instinct.
Which one is faster to get running?
It depends on the obstacle. Radio deploys faster where camera rigging and survey would be difficult or where sightlines are hostile, and a compressed production timeline is a legitimate reason to prefer it. Where the venue offers clean overhead positions and the rigging schedule has room, optical commissioning is unremarkable. Treat calibration and re-survey as scheduled work in either case, particularly if the show changes venues.