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RED Camera Sync and Trigger — DSMC1, DSMC2, Komodo, V-Raptor, Helium

Summary

Getting sync and trigger working with RED Digital Cinema cameras is consistently the most complex camera integration in the Flair community — RED's naming conventions are inverted from every other camera (the port labelled "Sync" carries start/stop, and the port labelled "Control" carries the sync pulse output), connector types vary by camera generation, and some bodies require specific expander modules to enable both sync AND start/stop simultaneously. This page documents the per-model requirements, GPIO settings, cable configurations, and known bugs. If in doubt: contact MRMC support (support@mrmoco.com) — they have model-specific cables available.

Community note: "Logic doesn't apply to (some) REDs. Start stop is sync and sync is trigger." — Peter Constan-Tatos

Symptoms

  • RED camera shows "Sync Internal" in camera display despite sync generator connected.
  • Flair shows correct sync frequency but camera does not lock phase ("No Sync Pulse" in Flair).
  • Camera starts/stops correctly but sync is lost — or sync works but camera won't start/stop.
  • Sync works on the first take but is lost when switching from playback back to record mode.
  • Phase drifts between takes despite signal appearing stable.

Community Guidance

[RESOLVED] Capability by Camera Model

Community — Timothy Heys Cerchio, community — 2020–2025

Camera Sync Output Notes
DSMC1 (Dragon, Epic, Raven) Full support Most compatible with MRMC Sync Cable. Uses CTRL port (Lemo-4 pin).
DSMC2 (Helium, Gemini, Scarlet) Base Expander ONLY V-Mount Expander does NOT work. Only Base Expander enables both sync AND start/stop.
Komodo / Komodo X Yes — with Expander Module or EXT port Requires RED's 3BNC-to-Lemo-00 Sync Cable or MRMC's EXT adapter.
V-Raptor Yes — EXT port (dedicated MRMC cable available) Now has a dedicated MRMC V-Raptor Trigger/Sync Cable (no blade needed).
V-Raptor XL Yes — CTRL port via Expander Blade Uses Lemo-00 CTRL + 3BNC Sync Cable.
Helium / Ranger Helium Yes — CTRL output No Sync port; use CTRL output with Lemo-00 to BNC adapter for sync. Flair 7.6.13 required for Bolt Jr.

Timothy Heys Cerchio: "DSMC1 is more (fully) compatible with the MRMC Sync cable — but DSMC2, unfortunately not! Unless it has a Base Expander fitted to it."

confidence_score: 0.90

[CRITICAL] RED Port Names Are Inverted

Community — Niko, Peter Constan-Tatos, Simon Wakley — 2020

RED's labelling is the opposite of every other camera system:

RED port label What it actually carries
CTRL Sync pulse output (what Flair needs to sync to camera)
SYNC Start/stop trigger (camera record start/stop)

Niko: "Remember that with RED cameras sync and control are the opposite you expect. Control is sync output and sync is start/stop recording."

Simon Wakley: "If the RED is set to output the state rather than the actual sync you will get a single reading and 'No Sync Pulse'. Make sure that the GPIO is set to sync output."

GPIO setting: In the RED camera menu, set GPIO → Sync Out on the CTRL port. Without this, Flair will see a single pulse (state change) rather than a continuous sync train.

confidence_score: 0.92

[RESOLVED] DSMC1 Setup — Standard MRMC Sync Cable

Community — Timothy Heys Cerchio — 2020

DSMC1 cameras (Dragon, Epic, Raven) work with the standard MRMC Sync Cable. Both sync AND start/stop are accessible through the single CTRL port using a 3-way BNC splitter:

  • White BNC = Start/Stop
  • Yellow BNC = Sync

Timothy Heys Cerchio: "You need to have TWO RED Lemo-3BNC Sync splitters to connect to Sync AND Ctrl."

Anton Vikström: "We got tired of the 3way splitters and made dedicated cables for ctrl and sync from flying lead Lemo-00 cables."

The MRMC Sync Cable switch settings for Epic/RED mode: SW1 = 0, SW2 = 1.

confidence_score: 0.88

[RESOLVED] DSMC2 Setup — Base Expander Required

Community — Timothy Heys Cerchio — 2020

DSMC2 bodies (Helium, Gemini, Scarlet, etc.) with a V-Mount Expander do NOT provide full sync+trigger functionality. Only a Base Expander enables both.

Timothy Heys Cerchio: "Only Base Expander will work both ways on DSMC2 bodies!! Only Base Expander takes 3.3v trigger on DSMC2 bodies."

Relay workaround (if Base Expander unavailable):

Niko: "If you attach a 3 volt relay in the middle of the sync cable (real sync, control for RED body) you can handle trigger with sync with the switch in Epic position."

For Gemini specifically with Base Expander:

Mike Greenberg: "Working with a Gemini with Base Expander, the GPIO menu settings look different than our Dragon. We have sync but no R/S."

confidence_score: 0.88

[RESOLVED] Komodo / Komodo X Setup

Community — Timothy Heys Cerchio, Ben Myers — 2021–2024

Timothy Heys Cerchio: "Komodo, with its own Expander Module, has a selectable Sync Output through the CTRL Port. Just like any other RED. You will still need the 3BNC-Lemo-00 Sync Cable from RED."

EXT port method (no expander blade required):

MRMC sells a 4-pin to 9-pin cable that connects to the RED EXT ports and connects right to the universal sync/trigger cable. RED also sells a 9-pin to flying lead cable for individual BNC connections.

Ben Myers: "MRMC sells a 4 pin to 9 pin cable that works with the RED EXT ports and connects right to the universal sync/trigger cable."

Known issue — intermittent failure:

Colin Michael Quinn: "I had two identical Komodos on set and one would not accept a Genlock signal. Tried every combination of cables and all that. Sometimes REDs just have gremlins in them."

confidence_score: 0.85

[CONFIRMED — MRMC official tutorial] Exact camera-menu path and how to verify sync is actually present:

  • The Komodo-specific camera setting to check is System Settings → GPO Function, which must be set to Sync Out (not the default Recording Indicator). This is the same setting described generically as "GPIO → Sync Out" above — this confirms the exact menu wording/path on Komodo specifically.
  • The Universal Sync Box has separate power/sync/trigger LEDs. It is powered from the robot side (the Alti box), not the camera, so expect no LED activity until the robot side is powered up. Once powered, the sync LED should immediately start pulsing at a rate matching the camera's configured frame rate (e.g. a 10fps camera produces a visible 10Hz pulse) — if that LED stays dark, the GPO Function setting above is the first thing to check.
  • The trigger/start-stop path is verified separately: Setup → External Camera in Flair has a test-trigger button that toggles the second LED and starts/stops the camera recording each time it's pressed — use this to confirm start/stop before relying on it during a real move.
  • Caution: plugging the sync/trigger cable into the camera can cause it to start recording immediately if the camera is already powered on — stop recording first, or connect the cable before powering the camera.

[RESOLVED] V-Raptor Setup — Dedicated MRMC Cable Available

Community — Timothy Heys Cerchio — January 2025

The V-Raptor has an EXT port. A dedicated MRMC V-Raptor Trigger/Sync Cable is now available that connects directly to the EXT port without requiring an Expander Blade.

Timothy Heys Cerchio: "To get both, you should purchase the new dedicated V-Raptor Trigger/Sync Cable from MRMC — which connects directly to the EXT port on Camera (without Blade)."

Timothy Heys Cerchio: "Also, be aware that the V-Raptor (not XL) will use the same cable adapter as the Komodo."

For the V-Raptor XL: uses CTRL port via Expander Blade with the standard Lemo-00 + 3BNC Sync Cable.

[CONFIRMED — MRMC official tutorial] V-Raptor XL splitter/port detail: using RED's own breakout cable with a 2-BNC MRMC splitter (white = trigger, yellow = sync) — the yellow (sync) BNC goes into the MRMC splitter, whose small Lemo connector plugs into the Raptor's CTRL port (confirmed this shows a live sync pulse in Flair immediately, matching the camera's set fps). The white (trigger/start-stop) BNC goes through a separate MRMC adapter cable ending in a Fisher connector, which plugs into either of the Raptor's two RS ports (RS1 or RS2 — video confirms both are equivalent). As with Komodo above, the camera can start recording as soon as this cable is first connected, so stop it before relying on Flair's own start/stop trigger test in Setup → External Camera.

Known issue — March 2026 Universal Sync Box failure:

Jeremy Andrews: "We haven't used our Milo crane for a while but yesterday we had a problem getting any sync pulse from a RED V-Raptor. This turns out to be a universal sync box failure. We have four of them and this one failed for no apparent reason."

If V-Raptor sync suddenly stops working on a rig that previously worked — check the Universal Sync Box hardware itself.

confidence_score: 0.88

[RESOLVED] Helium / Ranger Helium — Flair 7.6.13 Required

Community — Rapha — July 2025

Ranger Helium has no dedicated Sync port. Use the CTRL output:

Timothy Heys Cerchio: "Use the CTRL output and Lemo-00 to BNC adapter for use with the RED/Phantom MRMC Sync Cable."

Bug in older Flair builds:

Rapha: "Still struggling to get sync and trigger with RED Helium. I got the correct sync pulse in External Camera Setup / Test but each time I launch a record I got the 'No Sync Received' message."

Rapha (confirmed fix): "I confirm 7.6.13 fixed the sync issue (Bolt Jr / RED Helium)."

If you have Helium sync issues on Bolt Jr, update to Flair 7.6.13 or later.

confidence_score: 0.88

[KNOWN ISSUE] Sync Lost After Switching from Playback to Record

Community — Dan Gottesman, Timothy Heys Cerchio — November 2020

On RED Dragon 6K and likely other DSMC cameras:

Dan Gottesman: "Every time we switch from playback back to record mode on the camera, Flair will lose sync when I try to run the move. When we switch back to record, sync is coming in at 24 — despite the fact that the camera is set to 48."

Fix — set camera to "Brain" sync mode (not "Moco" or "Genlock"):

Timothy Heys Cerchio: "I think the best Sync setting for correct normal operation on the RED should be Brain (not Moco nor Genlock)."

confidence_score: 0.83

[KNOWN ISSUE] Erratic Sync at Non-Standard Frame Rates

Community — Simon Wakley — March 2021

At unusual frame rates (e.g. 47.95fps, 11.988fps), RED Monstro 8K was found to report wildly incorrect sync frequencies:

Simon Wakley: "We switched to 80.67 and the sync went to 80 ish and then back to 11.988. Don't trust sync on these RED cameras. All the evidence seems to suggest that the RED is misbehaving not the Flair software or sync pulse hardware."

At standard frame rates (24, 25, 30fps) sync is generally reliable.

confidence_score: 0.80

[INFORMATIONAL] When Sync Isn't Critical

Community — Simon Wakley — January 2025

Simon Wakley: "Sync is overrated. If you have a really fast move compared to a slow, mechanically it will not match perfectly due to flex in the arm and other factors... Where it does matter is more in fast pans and fast perspective shift when you are not rotoing and then it is vital. If in doubt sync, but don't waste hours trying to get sync working when it is not needed."

confidence_score: 0.88

[INFORMATIONAL] High Frame Rate Sync Margin — Why Sync May Not Matter at 240fps (2026-06-21)

Community — 49 179 1011493, Niko — 21 June 2026

At very high frame rates, the maximum possible timing error without any sync at all can be smaller than useful — reinforces the "when sync isn't critical" guidance above with concrete numbers:

"At 240fps your maximum error without sync is 1/480th second. If your moves are not extremely fast sync is irrelevant."

For Red Raptor specifically at 240fps, a genlock generator was preferred over Red's own frame-sync cable for reliability:

"Well in that case, use a genlock generator .. I found it easier and more reliable than Red frame sync cable! And set the genlock generator to your projects fps."

RED's in-camera "one shot sync" option was also raised as a stability fallback if standard sync appears intermittent:

Niko: "With a red raptor I had no problem to get sync from camera at 240 fps. If you feel some not stable sync use one shot sync option."

confidence_score: 0.75

[RESOLVED] V-Raptor / Komodo EXT Port Cable — Reconfirmed (2026-06-21)

Community — Ben Myers — 21 June 2026

Reconfirms the EXT-port method documented above, with the specific cable named plainly:

"With the Vraptor or Komodo (both use the 9 pin EXT port) you need the 9 pin lemo cable that connects to the 4 pin lemo on the universal cam sync/trigger kit. There might be other ways to trigger it but that's been the most stable and reliable for me."

confidence_score: 0.8

Additional Community Notes

[FORUM — talk.mrmoco.com] Universal Sync Box dip switch settings are incorrectly labelled for RED DSMC2 — the correct setting depends on which I/O Expander is fitted to the camera body, not the body generation alone.

The label printed on the Universal Sync Kit states "RED DSMC2" as a single setting, but this is wrong. There are two distinct DSMC2 expander types with different trigger circuit requirements:

Camera / Expander Trig switch Sync switch
ARRI 1 0
Phantom 1 1
RED DSMC1 0 1
RED DSMC2 — Base Expander 0 1 (same as DSMC1 — uses 3.3V signal)
RED DSMC2 — V-Lock I/O Expander 1 1 (uses contact-closure trigger circuit)

The Base Expander and V-Lock I/O Expander look nearly identical but require different dip switch positions. Using the wrong setting prevents sync or trigger. For confirmation, check the "Communication Ports" section of the DSMC2 user manual (around p.200) to identify which trigger circuit type the installed expander uses.

"An important note: Not all RED DSMC2 cameras will be fully functional with the 'Trig. 1 - Sync 1' setting. The setting of the dip switches has more to do with the I/O module attached to the camera." — jacob, talk.mrmoco.com

Source: Universal Sync Kit – RED camera models (2023-06-06, MRMC + jacob)

[CONFIRMED — MRMC official tutorial] Komodo and V-Raptor specifically: use 1/1 (both switches), not the 0/1 printed for "DSMC2." MRMC's own tutorial video demonstrates this directly and calls out that it's counter-intuitive: the Universal Sync Box's printed label table shows 1/1 as the Phantom setting, but for Komodo and V-Raptor — because of how these newer bodies handle the trigger/start-stop signal compared to older RED cameras — 1/1 is the setting that actually works, not the 0/1 shown for "old RED cameras" (DSMC1/early DSMC2) elsewhere on the same label. If you have a Komodo or V-Raptor and sync/trigger isn't working with the label's DSMC2 setting, try 1/1 before assuming a cable or expander fault.

DIY cable for RED V-Raptor / Komodo (EXT port) — bypasses expander modules.

Using the RED EXT-to-Flying-Lead cable (9-pin) with two BNC male connectors soldered on provides trigger and sync without any expander blade. Wiring: GND wire to sleeve/outer ring on both BNCs; GPI wire to Trigger BNC; GPO wire to Sync BNC.

@runimation's elegant variant: solder the three flying leads from a RED EXT cable directly to a LEMO FGG.0B connector — this mates with the universal sync box's 4-pin Lemo port and gives trigger + sync in a single cable with no breakout box. Confirmed working by multiple operators; set V-Raptor trigger mode to "Pulsed" for correct cut-on-slate and cut-at-end-of-move behaviour.

Source: RED V Raptor/Komodo Sync (2022–2025, TimHC + runimation + Mocojez)

Official Documentation