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Camera Sync and Trigger — Quick Reference

BOTH

Connecting camera sync and trigger correctly is one of the most common setup tasks in motion control. This page covers what sync and trigger are, how they differ, and provides the MRMC reference chart for all major camera models.

Sync vs Trigger — What's the Difference

Sync Trigger (Start/Stop)
What it does Locks Flair's move timing to the camera's shutter Tells the camera to start or stop recording
Signal direction Camera → Flair Flair → Camera
Required for Frame-accurate multi-pass compositing Starting/stopping the camera from Flair
Without it Flair runs at its own pace; passes may drift by a frame Camera must be started manually

For multi-pass layered work, sync is essential. Without a sync output from the camera, passes cannot be guaranteed to align frame-for-frame.

See also: Timecode vs Sync — Key Concepts

MRMC Camera Sync and Trigger Chart

Timothy Heys Cerchio compiled a comprehensive reference chart covering sync/trigger capabilities and cable requirements for all major cameras used with MRMC rigs.

Camera Sync and Trigger Chart V2 — covers RED, ARRI, Sony, Phantom, Blackmagic, DSLR families.

Camera Sync and Trigger Chart

Key Notes by Camera Family

ARRI Alexa Mini

  • Sync cable uses an EXT to RS adapter cable (ARRI part K2.0006170).
  • The Alexa Mini sync pulse varies in size with shutter angle — MRMC has an inline correction board for this.
  • Setting Ext. Control to NONE in Flair allows sync without triggering (camera starts/stops manually).
  • On Milo, a 24V stable power supply is needed for reliable sync signal through the arm cable. Insufficient supply voltage causes sync failures.

RED (DSMC1/DSMC2)

  • DSMC2 with Base Expander: full control (start/stop AND sync simultaneously).
  • Without DSMC2 Expander: must choose between start/stop OR sync — not both at once.
  • Sync cable: 4-pin Lemo to 3BNC (only 1 BNC per port actually used).

Phantom (Flex/VEO/Flex 4K)

  • Phantom Flex 4K: no sync output on camera body — requires Mini BOB (break-out box).
  • White BNC = trigger (Front Trigger in camera settings), Yellow BNC = Sync Out (set to F-Sync on camera).
  • Above ~200fps, frame-accurate sync becomes less critical and is commonly skipped.

Blackmagic Pocket 6K

  • No sync output. Only timecode-based triggering available (3.5mm audio jack, Jam-Lock).
  • Not recommended for multi-pass layered compositing — use an Alexa Mini or camera with sync output instead.
  • See: Blackmagic Pocket 6K — No Sync Output

One Shot Sync (all digital cameras)

Modern digital cameras generate jitter (slight frame-timing variation) because their frame clocks are derived by dividing a faster clock. Locking Flair to this jittery signal causes rough move execution.

Solution: Enable One Shot Sync in External Camera Setup. Flair locks to a single pulse, then runs the move at its own timing — eliminating jitter-induced roughness.

Source

  • TimHC, "Camera Sync and Trigger Chart" — talk.mrmoco.com/t/548 (2021-03-01)