Phantom VEO / Flex — Trigger Setup and High-Speed Sync Limits¶
Summary¶
Phantom high-speed cameras (VEO, Flex) are triggered via BNC connection directly to the Trigger Box output, using One Pulse mode in Flair. Above approximately 200fps, camera sync is not possible — only trigger start/stop is available. The end trigger on the VEO marks a partition cut (not a recording stop); to stop recording, use a front trigger pulse followed by an abort in Phantom CineStation/PCC. There is a cosmetic COM1 bug in some Flair versions that does not affect functionality.
Symptoms¶
- You need to configure Flair to trigger a Phantom VEO or Flex high-speed camera and are unsure which External Camera mode to use.
- The Phantom is not starting or stopping recording when the move runs, and you need the correct BNC wiring and pulse settings.
- You are shooting above 200 fps and need to understand why sync is not achievable at these speeds.
- The Phantom stops recording unexpectedly or a partition cut appears where you expected a clean stop.
- Flair's External Camera Setup is displaying
COM1and you are unsure whether this is affecting the trigger.
Camera Trigger Wiring¶
No sync cable or EXT-RS adapter required. The Phantom trigger input is a direct BNC switch-closure input.
Recommended pulse settings:
| Frame Rate | Pulse Width | Notes |
|---|---|---|
| 12fps or 15fps | 50ms | Standard for most shooting speeds |
| General | 12/50 or 15/50 | (pulse width / pulse length format) |
Flair External Camera Setup¶
Open Setups -> External Camera Setup in Flair.
| Setting | Value |
|---|---|
| Connection | One Pulse |
| Sync source | RT (or Network Board if using Ultibox) |
One Pulse is correct for Phantom
Unlike the ARRI Alexa Mini (which uses Pulsed), the Phantom uses One Pulse mode. Do not confuse these settings.
High Frame Rate Sync Limit¶
Above approximately 200fps, camera sync is not possible on the Phantom VEO/Flex. At these speeds:
- Trigger start/stop functions normally
- Phase-lock synchronisation (to eliminate frame rolling) cannot be achieved
- Plan shoots above 200fps without relying on multi-pass sync
No sync above ~200fps
This is a hardware limitation. At very high frame rates, the camera's sensor timing cannot be phase-locked to an external reference. Budget for this when planning multi-pass VFX shots.
End Trigger Behaviour — Partition Cut vs. Stop¶
The Phantom VEO handles an "end trigger" differently from most cameras:
- An end trigger signal does not stop recording
- It marks a partition cut in the Phantom's internal memory (splits the recording into a new segment)
- To actually stop recording after a move completes:
- Send a front trigger pulse (via Trigger Box output at end of move)
- Then manually abort in Phantom CineStation (PCC) software
Plan your PCC workflow
Operators working with Phantom on automated multi-pass shoots should plan their PCC abort workflow in advance. There is no way to stop Phantom recording via a single external trigger pulse alone.
COM1 Cosmetic Bug¶
In some versions of Flair, the External Camera serial connection selector may default to or display COM1 even when not in use. This is a cosmetic bug and has no effect on trigger functionality. Phantom triggering is BNC-based and does not use the serial connection at all — the COM1 display can be ignored.
WhatsApp Excerpts¶
- 2020-06-07 22:08 - Timothy Heys Cerchio said Phantom triggering is straightforward: strip a BNC cable into the Trigger Box, run down the rig BNC path, and connect to the camera Trigger port.
- 2020-06-07 22:09 - Timothy described this as the best way to do an end trigger for high-speed operation, where sync is not the main issue.
- 2020-06-07 22:13 - Timothy noted that the
One Pulseoption in External Camera Setup would ideally support front/end selection. - 2020-06-07 23:13 - Tom D asked whether an end trigger actually stops Phantom VEO recording.
- 2020-06-07 23:19 - Timothy clarified that the end trigger defines the cut point of the partition recording; the partition still needs to fill.
- 2020-06-07 23:23 - Timothy said that, as far as he knew, VEO and Flex 4K above 96 fps do not allow Run/Stop mode, only multiple partitioning.
References¶
- MRMC Forum — Setting up a Phantom 4K in Flair (External Camera Setup)
- Phantom VEO / Flex user manual — Trigger Input section
- Flair Operator Manual — External Camera Setup (Flair Classic — Ch.5 Setups: External Camera Setup — p.90 · Flair 7 — Ch.5 Setups: External Camera Setup — p.52)