Chapter: Sync Issues
Overview
Sync covers camera synchronisation (to eliminate frame rolling in slow motion), genlock, SMPTE LTC timecode (for triggering moves from music/playback), camera trigger wiring, and bloop lights. This is a complex area because timecode and sync are very different signals that are often confused.
Key Concepts
| Term |
Definition |
| Sync |
Electronic signal that locks camera shutter phase to Flair's motion phase — prevents rolling in slow motion |
| Genlock |
Same as sync — "generator locking" the camera frame to an external reference |
| LTC |
SMPTE Longitudinal TimeCode — audio-rate signal that carries an absolute time value; used to trigger moves at a specific music/edit point |
| Tri-level sync |
HD sync format, carried on BNC; the most common sync signal used with modern cameras |
| Bloop light |
Flash of light in-frame used to mark the first frame of a move on camera — used for multi-pass alignment when precise sync is not available |
| Trigger |
Digital signal (pulse) from Flair to camera that starts/stops recording; NOT the same as sync |
| One Pulse |
Flair trigger mode — single short pulse to start recording; preferred over Continuous High |
| RT-14 |
MRMC real-time control unit; has LTC input (3.5mm) and sync/trigger output (BNC and DB9) |
| TC Comparator |
Flair mode that waits for an incoming LTC value to match a set trigger point before firing the robot |
Sync vs Timecode — Key Distinction
These are entirely different signals:
|
Sync / Genlock |
LTC Timecode |
| Purpose |
Lock camera frame phase to robot |
Trigger robot at a specific clock time |
| Signal type |
Electronic sync pulse (BNC) |
Audio-rate signal (3.5mm jack) |
| RT14 port |
BNC output |
3.5mm input |
| When needed |
Multi-pass, slow motion, VFX |
Music video, playback-triggered shots |
| Without it |
Frame rolling visible in slow motion |
No automatic timing of moves |
RT14 Wiring Reference
| Port |
Signal |
Connector |
| LTC In |
SMPTE timecode input |
3.5mm TRS: RING = signal, SLEEVE = GND |
| Sync Out |
Tri-level sync output |
BNC |
| Trigger |
Camera trigger output |
DB9 / BNC depending on rig |
Note: RT14 has no LTC output (unlike older RT12). The RT14 can only receive timecode, not generate it.
Camera Sync Compatibility Notes
| Camera |
Sync method |
Notes |
| Phantom VEO / Flex |
BNC trigger direct to Trigger Box |
No sync needed for trigger; sync possible via BNC |
| Sony Venice 1 |
Not supported |
No sync output at all |
| Sony Venice 2 |
External sync generator only |
Rialto mechanical cabling/body placement is a separate rigging issue |
| RED V-Raptor |
Needs Expander Module |
BNC sync with Expander; trigger via CTRL port |
| RED Komodo |
Needs Expander Module (B-Box) |
Sync via CTRL port + 3BNC-Lemo00 cable |
| ARRI Alexa |
Tri-level BNC |
Standard setup |
| Blackmagic URSA |
BNC trigger |
BMPCC4K has no sync input |
| RED (most models) |
Shutter Sync via CTRL port |
Can output different video rate than capture rate |
Issue Index
Official Documentation References